$$A=k(t-2)^2,\qquad k0.$$ When $t=5$, $A=18$. Find $k$. Find the other value of $t$

Question

$$A=k(t-2)^2,\qquad k>0.$$ When $t=5$, $A=18$. Find $k$. Find the other value of $t$ that gives $A=18$. Find all values of $t$ for which $A\le18$. Does increasing $t$ always increase $A$? Justify with a numerical example.

Accepted Answer

(a) $2$; (b) $-1$; (c) $-1\le t\le5$; (d) No.

Direct and Inverse Proportion

Direct and Inverse Proportion

Solution:

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