The functions f and g are defined by f(x) = 2x2 and g(x) = (3x-2)/(x+1). Find fog(x).

Mathematics
The functions f and g are defined by f(x) = 2x2 and g(x) = (3x-2)/(x+1). Find fog(x).

ScanSolve AI Answer

Answer

18x224x+8x2+2x+1\frac{18x^2 - 24x + 8}{x^2 + 2x + 1}

Step 1: Identify the given functions. The functions are defined as: f(x)=2x2f(x) = 2x^2 g(x)=3x2x+1g(x) = \frac{3x-2}{x+1}

Step 2: Understand the composite function (fg)(x)(f \circ g)(x). The notation (fg)(x)(f \circ g)(x) means f(g(x))f(g(x)). This involves substituting the entire function g(x)g(x) into f(x)f(x) wherever 'x' appears in f(x)f(x).

Step 3: Substitute g(x)g(x) into f(x)f(x). Replace xx in f(x)=2x2f(x) = 2x^2 with g(x)=3x2x+1g(x) = \frac{3x-2}{x+1}: f(g(x))=2(3x2x+1)2f(g(x)) = 2\left(\frac{3x-2}{x+1}\right)^2

Step 4: Simplify the expression. Square the fraction: f(g(x))=2(3x2)2(x+1)2f(g(x)) = 2 \cdot \frac{(3x-2)^2}{(x+1)^2} Expand the numerator (3x2)2(3x-2)^2 and the denominator (x+1)2(x+1)^2: (3x2)2=(3x)22(3x)(2)+(2)2=9x212x+4(3x-2)^2 = (3x)^2 - 2(3x)(2) + (-2)^2 = 9x^2 - 12x + 4 (x+1)2=x2+2(x)(1)+12=x2+2x+1(x+1)^2 = x^2 + 2(x)(1) + 1^2 = x^2 + 2x + 1 Substitute these expanded forms back into the expression: f(g(x))=29x212x+4x2+2x+1f(g(x)) = 2 \cdot \frac{9x^2 - 12x + 4}{x^2 + 2x + 1} Multiply the numerator by 2: f(g(x))=2(9x212x+4)x2+2x+1f(g(x)) = \frac{2(9x^2 - 12x + 4)}{x^2 + 2x + 1} f(g(x))=18x224x+8x2+2x+1f(g(x)) = \frac{18x^2 - 24x + 8}{x^2 + 2x + 1}

The composite function is: 18x224x+8x2+2x+1\boxed{\frac{18x^2 - 24x + 8}{x^2 + 2x + 1}}

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