If sec A =5/4 and A is an angle in Quadrant IV, find the value of cos A.
A. -4/5
B.4/5
C.-5/4
Is it choice A
cos = 1/sec = 4/5
cos is positive in Quadrant 4, x is positive and hypotenuse is positive.
Thank you
You are welcome.
To find the value of cos A, we can use the identity that relates secant and cosine:
sec A = 1 / cos A
Given sec A = 5/4, we can substitute this value into the identity:
5/4 = 1 / cos A
We can solve this equation for cos A by taking the reciprocal of both sides:
4/5 = cos A
Therefore, the value of cos A is 4/5.
So, the correct answer is choice B: 4/5.