\( 1 \leftarrow \) For \( f(x)=3 x-3 \) and \( g(x)=4 x^{2}-3 \), find the following functions. a. \( (f \circ g)(x) ; \) b. \( (g \circ f)(x) ; \) c. \( (f \circ g)(-2) \), d. \( (g \circ f)(-2) \) a. \( (f \circ g)(x)=12 x^{2}-12 \) (Simplify your answer.) b. \( (g \circ f)(x)= \) (Simplify your answer.)
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To find \( (g \circ f)(x) \), we first substitute \( f(x) \) into \( g(x) \). Starting with \( f(x) = 3x - 3 \), we need to substitute this into \( g(x) \): \[ g(f(x)) = g(3x - 3) = 4(3x - 3)^2 - 3. \] Now, let's expand \( (3x - 3)^2 \): \[ (3x - 3)^2 = 9x^2 - 18x + 9. \] So, \[ g(f(x)) = 4(9x^2 - 18x + 9) - 3 = 36x^2 - 72x + 36 - 3. \] Now simplifying this gives: \[ g(f(x)) = 36x^2 - 72x + 33. \] Thus: b. \( (g \circ f)(x) = 36x^2 - 72x + 33. \) Now, for \( (f \circ g)(-2) \): From part a, \( (f \circ g)(x) = 12x^2 - 12 \), we substitute \( -2 \) into this function: \[ (f \circ g)(-2) = 12(-2)^2 - 12 = 12 \cdot 4 - 12 = 48 - 12 = 36. \] Therefore: c. \( (f \circ g)(-2) = 36. \) Finally, for \( (g \circ f)(-2) \): We will plug in \( -2 \) into \( g(f(x)) = 36x^2 - 72x + 33 \): \[ (g \circ f)(-2) = 36(-2)^2 - 72(-2) + 33 = 36 \cdot 4 + 144 + 33 = 144 + 144 + 33 = 321. \] Thus: d. \( (g \circ f)(-2) = 321. \)