Given tan theta 34 and sin theta 0 find cos theta2Solution

Given tan theta = 3/4 and sin theta > 0, find cos (theta/2).

Solution

3. tan theta=3/4   and sin theta>0. It means cos theta>0 too

here opposite=3   and adjacent=4

hypotenuse=sqrt(16+9)=5

cos theta= 4/5

cos theta/2= sqrt(1+cos theta)/2 = (1+4/5)/2 = sqrt(9/10)= (3/10)sqrt10