Answer:
-21
Step-by-step explanation:
f(-3) = -4(-3)² + 15 = -4(9) + 15 = -36 + 15 = -21
Any context to this question?
Answer:
B
Step-by-step explanation:
The parent function :> I'm not exactly 100% sure but I think this is what I remember it being!
Take into account, that in general, a cosine function of amplitude A, period T and vertical translation b, can be written as follow:

In the given case, you have:
A = 4
T = 3π/4
b = -3
By replacing you obtain:

Hence, the answer is:
f(x) = 4cos(8/3 x) - 3
Answer:
<em>π/2 and π/3</em>
Step-by-step explanation:
Given the equation 2cos²x - cosx = 0, to find the solution to the equation, we will follow the following step.
let P = cosx
The equation becomes 2P²-P = 0
P(2P-1) = 0
P = 0 and 2P-1 = 0
P= 0 and P = 1/2
Since P = cosx
cosx = 0 and cos(x) = 1/2
If cos(x) = 0
x = cos⁻¹0
x = 90⁰
x = π/2
If cos(x) = 1/2
x = cos⁻¹1/2
x = 60⁰
x = π/3
<em>Hence the solutions to the equation are π/2 and π/3.</em>