[" 2.If "cos x=(-3)/(5)" and "pi

If cos x=(-3)/(5) " and " pi lt x lt .(3pi)/(2) find the value of (i) "sin 2x "" ""(ii) cos 2x "" ""(iii) tan 2x "

If cos x=(-3)/(5) " and " .(pi)/(2) lt x lt pi find the values of (i) " sin .(x)/(2) " " (ii) " cos " (x)/(2) " " (iii) " tan " (x)/(2)

If cos x=-(3)/(5) and pi

If cos x=-(3)/(5) and pi

Find cos (x - y), given that cos x = - (4)/(5) with pi lt x lt (3pi)/(2) and sin y = - (24)/(25) with pi lt y lt (3pi)/(2) .

Prove that the roots of the equation 8x^(3)-4x^(2)-4x+1=0 " are " cos""pi/7, cos""(3pi)/7 " and " cos""(5pi)/7 . Evaluate sec""pi/7+sec""(3pi)/7+sec""(5pi)/7

The roots of the equation 8x^(3)-4x^(2)-4x+1=0 " are " cos""pi/7, cos""(3pi)/7 " and " cos""(5pi)/7 . Evaluate sec""pi/7+sec""(3pi)/7+sec""(5pi)/7

Prove that the roots of the equation 8x^(3)-4x^(2)-4x+1=0 " are " cos""pi/7, cos""(3pi)/7 " and " cos""(5pi)/7 . Evaluate sec""pi/7+sec""(3pi)/7+sec""(5pi)/7

The value of cos[(1)/(2)cos^(-1)(cos(-(14 pi)/(5)))] is/are a.cos (-(7 pi)/(5)) b.sin((pi)/(10))ccos((2 pi)/(5))d.-cos((3 pi)/(5))

Range of 3cos x+5sin(x-(pi)/(6)) is