<p>Test 1 - Section 7 - #18.</p>
<p>The graph above shows the function g, where g(x)=k(x+3)(x-3) for some contant k. If g(a-1.2)=0 and a>0, what is the value of a?</p>
<p>There's some graph, not sure if its necessary. Its a parabola.</p>
<p>anyone? w</p>
<p>ok so first note that a is positive. now since it says g(a-1.2)=0 , you plugin (a-1.2) for x.
then you get k(a-1.2+3)(a-1.2-3)…when you simplify that you get k(a+2.8)(a-4.2). now note that k is constant…so basically forget k. now you just solve the roots to get a. a can equal to 4.2 and -2.8 but since they want positive you stick with 4.2.</p>
<p>k won’t make a difference. x + 3 will be negative. the only positive value for x will occur at x - 3.
x - 3 = 0
a - 1.2 - 3 = 0
a = 4.2</p>