find exact value of cosine Theta for an angle Theta with a sine theta equals 3/8 and with its terminal side in quadrant 1

Answer:
B
Step-by-step explanation:
Choice A is incorrect. Nothing is minus in quad 1.
Cos(theta) = sqrt(1 - sin^2(theta) )
Cos(theta) = sqrt(1 - (3/8)^2 )
Cos(theta) = sqrt(1 - 9/64)
cos(theta) = sqrt(55)/sqrt(64)
Cos(theta) = sqrt(55) / 8
Looks like B
Note: you should do this one before any of the others. It uses all the same general principles as the others.