Math, asked by diya1398, 1 year ago

Prove cos30= root3/2

Answers

Answered by sourishdgreat1
9
Consider a right traingle ABC right angles at B  such that    ∠A=60°   and ∠C=30°

Note that if a right triangle has angles 30°, 60° and 90°, then the side opposite to ∠C is exactly one half the hypotenuse.So if the hypotenuse is 2, then the opposite side to ∠C  is 1Use pythagoras theorem to get,     AB2+BC2=AC2     (1)2+BC2=(2)2         1+BC2=4                BC2=3                  BC=3√Now since cosine is the ratio of the length of the base to the length of the hypotenuse.Thuis gives,     cosC=BCACwhich further implies that,    cos30°=3√2
Attachments:
Answered by jahanvisharma2910200
2

here is your answer in above picture.....

Attachments:
Similar questions