Question

2. If sin 0 = 4/5 then find cos 0​

Answer 1

Answer: cos(theta) = 3/5

Step-by-step explanation:

If sin(theta) = 4/5, what is the value of cos(theta) in quadrant 1?

sin^2(theta) + cos^2(theta) = 1

(4/5)^2 + cos^2(theta) = 1

16/25 + cos^2(theta) = 1

cos^2(theta) = 1 - 16/25

cos^2(theta) = 25/25 - 16/25

cos^2(theta) = (25 - 16)25

cos^2(theta) = 9/25

cos(theta) = sqrt(9/25) ... we are in quadrant I, so cos(theta) > 0

cos(theta) = 3/5

Answer 2

Step-by-step explanation:

sin^2teta+cos^2teta=1

cos^2teta=1-sin^2teta

=1-(4/5)^2

=1-16/25

=(25-16)/25

=9/25

Taking square root of both sides.

cos teta=3/5