Without using trigonometric tables , prove the following:

(ii) sin11 cos79 + cos 11 sin79 = 1

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Solution

sin79×cos11 + cos79×sin 11
we have to change one of the value from both side because it is a question based on complementary angles.
so
cos11× cos11 + cos79×sin11=
cos11×cos11 + sin11×sin11=
cos211 + sin211
and we have the identity sin2theta +cos2teetha = 1
by the above identity we have 1
so answer or the value of
sin79cos11 +cos79sin11= 1

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