Given f(x) = (3x - 2)/(5x + 4) and g(x) = (7x + 2)/(4x - 3), find (a) f^-1(x), (b) g^-1(x), and (c) the values of x if g^-1(x) = 1 - f^-1(x).
|Mathematics
Given f(x) = (3x - 2)/(5x + 4) and g(x) = (7x + 2)/(4x - 3), find (a) f^-1(x), (b) g^-1(x), and (c) the values of x if g^-1(x) = 1 - f^-1(x).
ScanSolve AI Answer
Answer
3−5x4x+2
Step 1: Find f−1(x) (Part a).
Let y=f(x), so y=5x+43x−2.
To find the inverse function, swap x and y:
x=5y+43y−2
Multiply both sides by (5y+4):
x(5y+4)=3y−25xy+4x=3y−2
Rearrange the terms to isolate y:
5xy−3y=−2−4x
Factor out y:
y(5x−3)=−2−4x
Solve for y:
y=5x−3−2−4x
This can be written as:
f^{-1}(x) = \mathbf{\frac{4x + 2{3 - 5x}}}
Step 2: Find g−1(x) (Part b).
Let y=g(x), so y=4x−37x+2.
To find the inverse function, swap x and y:
x=4y−37y+2
Multiply both sides by (4y−3):
x(4y−3)=7y+24xy−3x=7y+2
Rearrange the terms to isolate y:
4xy−7y=2+3x
Factor out y:
y(4x−7)=2+3x
Solve for y:
y=4x−72+3x
So,
g^{-1}(x) = \mathbf{\frac{3x + 2{4x - 7}}}
Step 3: Find the values of x if g−1(x)=1−f−1(x) (Part c).
Substitute the expressions for f−1(x) and g−1(x) into the equation:
4x−73x+2=1−3−5x4x+2
First, simplify the right side:
1−3−5x4x+2=3−5x3−5x−3−5x4x+2=3−5x(3−5x)−(4x+2)=3−5x3−5x−4x−2=3−5x1−9x
Now the equation is:
4x−73x+2=3−5x1−9x
Cross-multiply:
(3x+2)(3−5x)=(1−9x)(4x−7)
Expand both sides:
9x−15x2+6−10x=4x−7−36x2+63x−15x2−x+6=−36x2+67x−7
Move all terms to one side to form a quadratic equation:
−15x2+36x2−x−67x+6+7=021x2−68x+13=0
Use the quadratic formula x=2a−b±b2−4ac with a=21, b=−68, c=13:
x=2(21)−(−68)±(−68)2−4(21)(13)x=4268±4624−1092x=4268±3532
Calculate the square root:
3532≈59.43063
Now find the two values for x:
x1=4268+59.43063=42127.43063≈3.03406x2=4268−59.43063=428.56937≈0.20398
Rounding to two decimal places:
x1≈3.03x2≈0.20
The values of x are 3.03 and 0.20.
That's 2 down. 3 left today — send the next one.
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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
Step 1: Find f^-1(x) (Part a). Let y = f(x), so y = (3x - 2)/(5x + 4). To find the inverse function, swap x and y: x = (3y - 2)/(5y + 4) Multiply both sides by (5y + 4): x(5y + 4) = 3y - 2 5xy + 4x = 3y - 2 Rearrange the terms to isolate y: 5xy - 3y = -2 - 4x Factor out y: y(5x - 3) = -2 - 4x Solve for y: y = (-2 - 4x)/(5x - 3) This can be written as: f^-1(x) = (4x + 2)/(3 - 5x) Step 2: Find g^-1(x) (Part b). Let y = g(x), so y = (7x + 2)/(4x - 3). To find the inverse function, swap x and y: x = (7y + 2)/(4y - 3) Multiply both sides by (4y - 3): x(4y - 3) = 7y + 2 4xy - 3x = 7y + 2 Rearrange the terms to isolate y: 4xy - 7y = 2 + 3x Factor out y: y(4x - 7) = 2 + 3x Solve for y: y = (2 + 3x)/(4x - 7) So, g^-1(x) = (3x + 2)/(4x - 7) Step 3: Find the values of x if g^-1(x) = 1 - f^-1(x) (Part c). Substitute the expressions for f^-1(x) and g^-1(x) into the equation: (3x + 2)/(4x - 7) = 1 - (4x + 2)/(3 - 5x) First, simplify the right side: 1 - (4x + 2)/(3 - 5x) = (3 - 5x)/(3 - 5x) - (4x + 2)/(3 - 5x) = ((3 - 5x) - (4x + 2))/(3 - 5x) = (3 - 5x - 4x - 2)/(3 - 5x) = (1 - 9x)/(3 - 5x) Now the equation is: (3x + 2)/(4x - 7) = (1 - 9x)/(3 - 5x) Cross-multiply: (3x + 2)(3 - 5x) = (1 - 9x)(4x - 7) Expand both sides: 9x - 15x^2 + 6 - 10x = 4x - 7 - 36x^2 + 63x -15x^2 - x + 6 = -36x^2 + 67x - 7 Move all terms to one side to form a quadratic equation: -15x^2 + 36x^2 - x - 67x + 6 + 7 = 0 21x^2 - 68x + 13 = 0 Use the quadratic formula x = -b ± sqrt(b^2 - 4ac)2a with a=21, b=-68, c=13: x = -(-68) ± sqrt((-68)^2 - 4(21)(13))2(21) x = 68 ± sqrt(4624 - 1092)42 x = 68 ± sqrt(3532)42 Calculate the square root: sqrt(3532) ≈ 59.43063 Now find the two values for x: x_1 = (68 + 59.43063)/(42) = (127.43063)/(42) ≈ 3.03406 x_2 = (68 - 59.43063)/(42) = (8.56937)/(42) ≈ 0.20398 Rounding to two decimal places: x_1 ≈ 3.03 x_2 ≈ 0.20 The values of x are 3.03 and 0.20. That's 2 down. 3 left today — send the next one.