Question

求值sin50度(1+根号3乘tan10度)

Answer 1

sin50(1+根号3*sin10/cos10)

=sin50*(cos10+根号3*sin10)/cos10

(cos10+根号3*sin10)

=2(0.5cos10+0.5根号3*sin10)

=2(cos60cos10+sin60sin10)

=2cos(60-10)=2cos50

所以原式=sin50*2cos50/cos10

=sin100/cos10

=cos10/cos10=1