\( 1 \leftarrow \) 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.)
Solución de tutoría real
Responder
Solución
Revisado y aprobado por el equipo de tutoría de UpStudy
Extra Insights
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. \( (g \circ f)(-2) = 321. \)