Question:
Let $f: R \rightarrow R$ and $g: R \rightarrow R$ be functions defined by $f(x)=5-x^{2}$ and $g(x)=3 x-4$. Then the value of fog $(-1)$ is___________.
Solution:
Given: $f(x)=5-x^{2}$ and $g(x)=3 x-4$
$f o g(-1)=f(g(-1))$
$=f(3(-1)-4)$
$=f(-3-4)$
$=f(-7)$
$=5-(-7)^{2}$
$=5-49$
$=-44$
Hence, the value of fog (–1) is –44.
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