Find the derivatives of the following with first principle: 1) f(x) = x2-x 2) f(x) = sqrt(x+1) 3) g(x) = 1/x2 4) h(x) = 1/sqrt(x) 5) y = 1/(2x-1)
|Mathematics
Find the derivatives of the following with first principle: 1) f(x) = x2-x 2) f(x) = sqrt(x+1) 3) g(x) = 1/x2 4) h(x) = 1/sqrt(x) 5) y = 1/(2x-1)
ScanSolve AI Answer
Answer
2x-1
Here are the derivatives of the given functions using the first principle:
1) f(x)=x2−x
Step 1: Write the definition of the derivative.
f′(x)=limh→0hf(x+h)−f(x)
Step 2: Substitute f(x+h) and f(x) into the formula.
f′(x)=limh→0h((x+h)2−(x+h))−(x2−x)
Step 3: Expand and simplify the numerator.
f′(x)=limh→0h(x2+2xh+h2−x−h)−(x2−x)f′(x)=limh→0hx2+2xh+h2−x−h−x2+xf′(x)=limh→0h2xh+h2−h
Step 4: Factor out h from the numerator and cancel it with the denominator.
f′(x)=limh→0hh(2x+h−1)f′(x)=limh→0(2x+h−1)
Step 5: Evaluate the limit by substituting h=0.
f′(x)=2x+0−1=2x−1
The derivative is 2x−1.
2) f(x)=x+1
Step 1: Write the definition of the derivative.
f′(x)=limh→0hf(x+h)−f(x)
Step 2: Substitute f(x+h) and f(x) into the formula.
f′(x)=limh→0hx+h+1−x+1
Step 3: Multiply the numerator and denominator by the conjugate of the numerator.
f′(x)=limh→0hx+h+1−x+1⋅x+h+1+x+1x+h+1+x+1
Step 4: Simplify the numerator using (a−b)(a+b)=a2−b2.
f′(x)=limh→0h(x+h+1+x+1)(x+h+1)−(x+1)f′(x)=limh→0h(x+h+1+x+1)h
Step 5: Cancel out h and evaluate the limit by substituting h=0.
f′(x)=limh→0x+h+1+x+11=x+0+1+x+11f′(x)=x+1+x+11=2x+11
The derivative is 2x+11.
3) g(x)=x21
Step 1: Write the definition of the derivative.
g′(x)=limh→0hg(x+h)−g(x)
Step 2: Substitute g(x+h) and g(x) into the formula.
g′(x)=limh→0h(x+h)21−x21
Step 3: Combine the fractions in the numerator.
g′(x)=limh→0hx2(x+h)2x2−(x+h)2g′(x)=limh→0hx2(x+h)2x2−(x2+2xh+h2)g′(x)=limh→0hx2(x+h)2−2xh−h2
Step 4: Factor out h from the numerator and cancel it with the denominator.
g′(x)=limh→0hx2(x+h)2h(−2x−h)g′(x)=limh→0x2(x+h)2−2x−h
Step 5: Evaluate the limit by substituting h=0.
g′(x)=x2(x+0)2−2x−0=x2⋅x2−2x=x4−2xg′(x)=−x32
The derivative is −x32.
4) h(x)=x1
Step 1: Write the definition of the derivative.
h′(x)=limh→0hh(x+h)−h(x)
Step 2: Substitute h(x+h) and h(x) into the formula.
h′(x)=limh→0hx+h1−x1
Step 3: Combine the fractions in the numerator.
h′(x)=limh→0hxx+hx−x+h=limh→0hxx+hx−x+h
Step 4: Multiply the numerator and denominator by the conjugate of the numerator.
h′(x)=limh→0hxx+hx−x+h⋅x+x+hx+x+hh′(x)=limh→0hxx+h(x+x+h)x−(x+h)h′(x)=limh→0hxx+h(x+x+h)−h
Step 5: Cancel out h and evaluate the limit by substituting h=0.
h′(x)=limh→0xx+h(x+x+h)−1h′(x)=xx+0(x+x+0)−1=xx(2x)−1h′(x)=x(2x)−1=−2xx1
The derivative is −2xx1.
5) y=2x−11
Step 1: Write the definition of the derivative.
dxdy=limh→0hf(x+h)−f(x)
Step 2: Substitute f(x+h) and f(x) into the formula.
dxdy=limh→0h2(x+h)−11−2x−11dxdy=limh→0h2x+2h−11−2x−11
Step 3: Combine the fractions in the numerator.
dxdy=limh→0h(2x+2h−1)(2x−1)(2x−1)−(2x+2h−1)dxdy=limh→0h(2x+2h−1)(2x−1)2x−1−2x−2h+1dxdy=limh→0h(2x+2h−1)(2x−1)−2h
Step 4: Cancel out h and evaluate the limit by substituting h=0.
dxdy=limh→0(2x+2h−1)(2x−1)−2dxdy=(2x+2(0)−1)(2x−1)−2=(2x−1)(2x−1)−2dxdy=−(2x−1)22
The derivative is −(2x−1)22.
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1) f(x) = x^2 - x Step 1: Write the definition of the derivative. f'(x) = _h 0 (f(x+h) - f(x))/(h) Step 2: Substitute f(x+h) and f(x) into the formula.
Find the derivatives of the following with first principle: 1) f(x) = x2-x 2) f(x) = sqrt(x+1) 3) g(x) = 1/x2 4) h(x) = 1/sqrt(x) 5) y = 1/(2x-1)
This mathematics problem involves applying core mathematical principles and formulas. Below you will find a complete step-by-step solution with detailed explanations for each step, helping you understand not just the answer but the method behind it.
ScanSolve AI Answer
Here are the derivatives of the given functions using the first principle: 1) f(x) = x^2 - x Step 1: Write the definition of the derivative. f'(x) = _h 0 (f(x+h) - f(x))/(h) Step 2: Substitute f(x+h) and f(x) into the formula. f'(x) = _h 0 (((x+h)^2 - (x+h)) - (x^2 - x))/(h) Step 3: Expand and simplify the numerator. f'(x) = _h 0 ((x^2 + 2xh + h^2 - x - h) - (x^2 - x))/(h) f'(x) = _h 0 (x^2 + 2xh + h^2 - x - h - x^2 + x)/(h) f'(x) = _h 0 (2xh + h^2 - h)/(h) Step 4: Factor out h from the numerator and cancel it with the denominator. f'(x) = _h 0 (h(2x + h - 1))/(h) f'(x) = _h 0 (2x + h - 1) Step 5: Evaluate the limit by substituting h=0. f'(x) = 2x + 0 - 1 = 2x - 1 The derivative is 2x-1. 2) f(x) = sqrt(x+1) Step 1: Write the definition of the derivative. f'(x) = _h 0 (f(x+h) - f(x))/(h) Step 2: Substitute f(x+h) and f(x) into the formula. f'(x) = _h 0 sqrt(x+h+1) - sqrt(x+1)h Step 3: Multiply the numerator and denominator by the conjugate of the numerator. f'(x) = _h 0 sqrt(x+h+1) - sqrt(x+1)h · sqrt(x+h+1) + sqrt(x+1)sqrt(x+h+1) + sqrt(x+1) Step 4: Simplify the numerator using (a-b)(a+b)=a^2-b^2. f'(x) = _h 0 ((x+h+1) - (x+1))/(h(sqrt(x+h+1) + x+1)) f'(x) = _h 0 (h)/(h(sqrt(x+h+1) + x+1)) Step 5: Cancel out h and evaluate the limit by substituting h=0. f'(x) = _h 0 (1)/(sqrt(x+h+1) + x+1) = (1)/(sqrt(x+0+1) + x+1) f'(x) = (1)/(sqrt(x+1) + x+1) = (1)/(2sqrt(x+1)) The derivative is (1)/(2sqrt(x+1)). 3) g(x) = (1)/(x^2) Step 1: Write the definition of the derivative. g'(x) = _h 0 (g(x+h) - g(x))/(h) Step 2: Substitute g(x+h) and g(x) into the formula. g'(x) = _h 0 (1)/((x+h)^2) - (1)/(x^2)h Step 3: Combine the fractions in the numerator. g'(x) = _h 0 (x^2 - (x+h)^2)/(x^2(x+h)^2)h g'(x) = _h 0 (x^2 - (x^2 + 2xh + h^2))/(h x^2(x+h)^2) g'(x) = _h 0 (-2xh - h^2)/(h x^2(x+h)^2) Step 4: Factor out h from the numerator and cancel it with the denominator. g'(x) = _h 0 (h(-2x - h))/(h x^2(x+h)^2) g'(x) = _h 0 (-2x - h)/(x^2(x+h)^2) Step 5: Evaluate the limit by substituting h=0. g'(x) = (-2x - 0)/(x^2(x+0)^2) = (-2x)/(x^2 · x^2) = (-2x)/(x^4) g'(x) = -(2)/(x^3) The derivative is -(2)/(x^3). 4) h(x) = (1)/(sqrt(x)) Step 1: Write the definition of the derivative. h'(x) = _h 0 (h(x+h) - h(x))/(h) Step 2: Substitute h(x+h) and h(x) into the formula. h'(x) = _h 0 (1)/(sqrt(x+h)) - (1)/(sqrt(x))h Step 3: Combine the fractions in the numerator. h'(x) = _h 0 sqrt(x) - sqrt(x+h)sqrt(x)sqrt(x+h)h = _h 0 sqrt(x) - sqrt(x+h)hsqrt(x)sqrt(x+h) Step 4: Multiply the numerator and denominator by the conjugate of the numerator. h'(x) = _h 0 sqrt(x) - sqrt(x+h)hsqrt(x)sqrt(x+h) · sqrt(x) + sqrt(x+h)sqrt(x) + sqrt(x+h) h'(x) = _h 0 (x - (x+h))/(hsqrt(x)x+h)(sqrt(x) + sqrt(x+h)) h'(x) = _h 0 (-h)/(hsqrt(x)x+h)(sqrt(x) + sqrt(x+h)) Step 5: Cancel out h and evaluate the limit by substituting h=0. h'(x) = _h 0 (-1)/(sqrt(x)x+h)(sqrt(x) + sqrt(x+h)) h'(x) = (-1)/(sqrt(x)x+0)(sqrt(x) + sqrt(x+0)) = (-1)/(sqrt(x)x)(2sqrt(x)) h'(x) = (-1)/(x(2sqrt(x))) = -(1)/(2xsqrt(x)) The derivative is -(1)/(2xsqrt(x)). 5) y = (1)/(2x-1) Step 1: Write the definition of the derivative. (dy)/(dx) = _h 0 (f(x+h) - f(x))/(h) Step 2: Substitute f(x+h) and f(x) into the formula. (dy)/(dx) = _h 0 (1)/(2(x+h)-1) - (1)/(2x-1)h (dy)/(dx) = _h 0 (1)/(2x+2h-1) - (1)/(2x-1)h Step 3: Combine the fractions in the numerator. (dy)/(dx) = _h 0 ((2x-1) - (2x+2h-1))/((2x+2h-1)(2x-1))h (dy)/(dx) = _h 0 (2x-1-2x-2h+1)/(h(2x+2h-1)(2x-1)) (dy)/(dx) = _h 0 (-2h)/(h(2x+2h-1)(2x-1)) Step 4: Cancel out h and evaluate the limit by substituting h=0. (dy)/(dx) = _h 0 (-2)/((2x+2h-1)(2x-1)) (dy)/(dx) = (-2)/((2x+2(0)-1)(2x-1)) = (-2)/((2x-1)(2x-1)) (dy)/(dx) = -(2)/((2x-1)^2) The derivative is -(2)/((2x-1)^2). That's 2 down. 3 left today — send the next one.