If `tan((pi)/(4)+phi)=(1)/(3)`,then the value of `cos2 phi` is

If tan phi=(4)/(3), then the value of tan3 phi, is

If tan theta=(1)/(2) and tan phi=(1)/(3), then the value of theta+phi is

If tan theta = 1 and sin phi = (1)/( sqrt(2)) , then the value of cos (theta + phi) is

If tan((theta)/(2))=5/2and tan((phi)/(2))=3/4, the value of cos(theta+phi), is

If tan theta = 1 and sin phi = (1)/(sqrt(2)), and theta, phi in[0,pi/2] , then the value of cos (theta + phi) is