Q25. Show that:
cos’ (45° + 0)+cos (45°-9
tan (60° + 0) tan (30-0)
=1​

1 thought on “Q25. Show that:<br />cos’ (45° + 0)+cos (45°-9<br />tan (60° + 0) tan (30-0)<br />=1​”

1. Step-by-step explanation:

   We know, 2cos2x=1+cos2x.

   ∴cos2x=21+cos2x

   cos2(455+θ)=21+cos(90o+θ)=21−sinθ

   cos2(45o−θ)=21+cos(900−θ)=21+sinθ

   tan(60o+θ)=1−tan60otanθtan60o+tanθ=1−3tanθ3+tanθ

   tan(30o−θ)=1+tan30otanθtan30o−tanθ=

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