1.

Evaluate sin 105°+cos 105°

Answer» Sin 150=sin(45+60)Sin (a+b)=sin a cos b+cos a sin b=sin45×cos60+cos45×sin60=(1/root2×1/2)+(1/root2×root3/2)=1/2root2+root3/2root2=1+root3/2root2
Write 105° as (45+60)° and then use the formula sin(a+b) and cos(a+b)


Discussion

No Comment Found