Q. 33.7( 28 Votes )

Evaluate sin 60°

Answer :

Let us first solve sin 60° cos 30° + sin 30° cos 60°.

We know,


sin 60° = √3/2


cos 30° = √3/2


sin 30° = 1/2


& cos 60° = 1/2


So, sin 60° cos 30° + sin 30° cos 60° =


sin 60° cos 30° + sin 30° cos 60° =


sin 60° cos 30° + sin 30° cos 60° = 1 …(i)


Now, for sin (60° + 30°):


sin (60° + 30°) = sin 90°


sin (60° + 30°) = 1 [, sin 90° = 1] …(ii)


By equations (i) & (ii), we can conclude that


sin (60° + 30°) = sin 60° cos 30° + sin 30° cos 60°


And infact in general, let 60° = x and 30° = y. Then,


sin (x + y) = sin x cos y + sin y cos x


Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Trigonometric RatiosTrigonometric RatiosTrigonometric Ratios46 mins
Trigonometric Ratios of Specified AnglesTrigonometric Ratios of Specified AnglesTrigonometric Ratios of Specified Angles38 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses
RELATED QUESTIONS :

Evaluate the follAP- Mathematics

Show that <span lAP- Mathematics

Evaluate

<
AP- Mathematics

If tan A = cot B AP- Mathematics

Evaluate

<
AP- Mathematics

Show that <span lAP- Mathematics

Show that

AP- Mathematics

Evaluate

<
AP- Mathematics

If tan2A = cot(A AP- Mathematics

Show that <span lAP- Mathematics