Question

If $f\left(x\right)=12x^5$ and $g\left(x\right)=-3x^2$, determine $(f.g)(-1)$
$[Given:(f.g\left)\right(x)$=$f\left(x\right).g\left(x\right)]$

• A. $36$
• B. $42$
• C. $32$
• D. $-36$

Answer 1

The correct option is A $36$

$(f.g)\left(x\right)=f\left(x\right)\cdot g\left(x\right)$

$=\left(12x^5\right)(-3x^2)$

$=-36x^7$
$(f.g)(-1)=-36(-1{)}^7$

$=-36(-1)$

$=36$