Question

if Sin(theta) = 4/5 and is in the second quadrant, the value of cos(theta) is?

Answer 1

In the 2nd quadrant, sin and csc are positive. Therefore, cosine is negative

Answer 2

Draw a triangle, using the definition of sine

Answer 3

Oh Okay Thanks ^^ much appreciated I was over thinking

Answer 4

Find side b, then find use the definition of cosine to find the cosine

*Oops, let me fix the drawing, one side should be negative

Answer 5

*never mind, only side b is negative. I 2nd guessed myself

Answer 6

I see, but going off the rule it would be 3 right however since it is in Quadrant 2 it would be negative right?

Answer 7

5^2 = 4^2 + x^2

Yes, side b would be -3

Now what is the cosine?

Answer 8

-3/5

Answer 9

Yes, -3/5

Answer 10

Thank you ! ^^