So lets get to the problem
<span>165°= 135° +30° </span>
<span>To make it easier I'm going to write the same thing like this </span>
<span>165°= 90° + 45°+30° </span>
<span>Sin165° </span>
<span>= Sin ( 90° + 45°+30° ) </span>
<span>= Cos( 45°+30° )..... (∵ Sin(90 + θ)=cosθ </span>
<span>= Cos45°Cos30° - Sin45°Sin30° </span>
<span>Cos165° </span>
<span>= Cos ( 90° + 45°+30° ) </span>
<span>= -Sin( 45°+30° )..... (∵Cos(90 + θ)=-Sinθ </span>
<span>= Sin45°Cos30° + Cos45°Sin30° </span>
<span>Tan165° </span>
<span>= Tan ( 90° + 45°+30° ) </span>
<span>= -Cot( 45°+30° )..... (∵Cot(90 + θ)=-Tanθ </span>
<span>= -1/tan(45°+30°) </span>
<span>= -[1-tan45°.Tan30°]/[tan45°+Tan30°] </span>
<span>Substitute the above values with the following... These should be memorized </span>
<span>Sin 30° = 1/2 </span>
<span>Cos 30° =[Sqrt(3)]/2 </span>
<span>Tan 30° = 1/[Sqrt(3)] </span>
<span>Sin45°=Cos45°=1/[Sqrt(2)] </span>
<span>Tan 45° = 1</span>
Find the value of r(q(4)), so first you need to find the value of q(4).
q(4), this means that x = 4, so substitute/plug it into the equation to find the value of q(x) when x = 4:
q(x) = -2x - 1 Plug in 4 into "x" since x = 4
q(4) = -2(4) - 1
q(4) = -8 - 1
q(4) = -9
Now that you know the value of q(4), you can find the value of r(x) when x = q(4)
r(x) = 2x² + 1
r(q(4)) = 2(q(4))² + 1 Plug in -9 into "q(4)" since q(4) = -9
r(q(4)) = 2(-9)² + 1
r(q(4)) = 2(81) + 1
r(q(4)) = 163 163 is the value of r(q(4))
Answer:
D
Step-by-step explanation:
7.50/10=0.75
0.75*6=4.5
So, you will get 6 batteries for $4.50 which of course is less than $4.95.
The mixed number would be 1 and 1/2.
