finding the angles
(a) cos(50°) cos(22°) + sin(50°) sin(22°) = cos( °)

(b) cos(16°) sin(7°) - sin(16°) cos(7°) = sin( °)

(c) cos(5°) sin(-4°) - cos(4°) sin(5°) = sin( °)

Question

finding the angles 
(a) cos(50°) cos(22°) + sin(50°) sin(22°) = cos(   °)

(b) cos(16°) sin(7°) - sin(16°) cos(7°) = sin(   °)

(c) cos(5°) sin(-4°) - cos(4°) sin(5°) = sin(   °)

anonymous · Answer

Do you know the sum and difference formulae of trigonometric ratios

anonymous · Answer

no

anonymous · Answer

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anonymous · Answer

just check which question can be replaced by which identity and check the values.
For example, in the first one
the fourth identity is used.where A = 50and B = 22 and the answer is cos(50 - 22) = cos28

anonymous · Answer

can you similarly do the second and third ones??