Mathematic Problems
192. példa

Calculate the following expression for α=30°.

{formula_1502}
4-sin α1-sin α-254cos2 α+21+sin α
=4-sin 30°1-sin 30°-254cos2 30°+21+sin 30°
=4-121-12-254322+21+12
=8-122-12-25434+22+12
=7212-253+232
=7·22·1-253+2·23
=7-253+43
=21-25+43
=0
4-sin α1-sin α-254cos2 α+21+sin α=0