Sorry I can't read it,
otherwise i would be happy to help you
Answer:
B: 280
Step-by-step explanation:
The regression line predicts that when x equals 5:
In order to find the value for y, one must simply apply the following logarithmic property:
if : 
then: 
Applying it to this particular problem:
Therefore, the regression line predicts y will equal 280 when x equals 5.
We are given with
P(pop quiz) = 60%
P(not do homework) = 85%
And the condition that
P (pop quiz and do homework) > 5%
So,
P (pop quiz) x P (do homework)
P (pop quiz) x ( 1 - P (not do homework) )
60% x ( 1 - 85%)
The result is greater than five percent so he will not do his homework.
Write the left side of the given expression as N/D, where
N = sinA - sin3A + sin5A - sin7A
D = cosA - cos3A - cos5A + cos7A
Therefore we want to show that N/D = cot2A.
We shall use these identities:
sin x - sin y = 2cos((x+y)/2)*sin((x-y)/2)
cos x - cos y = -2sin((x+y)/2)*sin((x-y)2)
N = -(sin7A - sinA) + sin5A - sin3A
= -2cos4A*sin3A + 2cos4A*sinA
= 2cos4A(sinA - sin3A)
= 2cos4A*2cos(2A)sin(-A)
= -4cos4A*cos2A*sinA
D = cos7A + cosA - (cos5A + cos3A)
= 2cos4A*cos3A - 2cos4A*cosA
= 2cos4A(cos3A - cosA)
= 2cos4A*(-2)sin2A*sinA
= -4cos4A*sin2A*sinA
Therefore
N/D = [-4cos4A*cos2A*sinA]/[-4cos4A*sin2A*sinA]
= cos2A/sin2A
= cot2A
This verifies the identity.
