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Given the function $h(x)=3 x^2 + 5$, evaluate $h(-4)$.

My friend's tutor says its $h(-4)=149$ but isn't it $h(-4)=53$

David G. Stork
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kero
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    It's $53$. But $h(x)=(3x)^2+5$ would give $h(-4)=149$ so maybe you should check that you read the question correctly. – David Dec 13 '18 at 01:16

1 Answers1

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To evaluate $h(-4)$, you plug in $x = -4$ into $h(x)$.

Thus, so far,

$$h(-4) = 3(-4)^2 + 5$$

Per the order of operations, we do the exponentiation first. $(-4)^2 = 16$. From there, we multiply by $3$ and add $5$, again per the order of operations. Thus,

$$h(-4) = 3(-4)^2 + 5 = 3(16) + 5 = 48 + 5 = 53$$

i.e. your friend's tutor is wrong. My guess is they multiplied $3(-4)$ first and then squared that and added $5$. That would explain the $149$, which is wrong since they went out of order.

PrincessEev
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