Math, asked by sunilkumar12377, 1 year ago

i need it step please

Attachments:

Answers

Answered by bijaythapa

sin780.cos30+cos120.sin390
=sin(360+420).cos30+cos120.sin(360+30)
=sin420.cos30+cos120.sin30
=sin(360+60).cos30+cos120.sin30
=sin60.cos30+cos120.sin30
=(√3/2).(√3/2)+(-1/2).(1/2)
=(3/4)-(1/4)
=(3-1)/4
=2/4
=1/2

this is your full answer i hope this will help you

sunilkumar12377: how did you got the answer for cos120

bijaythapa: cos120 means cos 60 since cos is negative in second quadrant it has negative value -1/2 of cos60(1/2)

Previous Question

Next Question

Similar questions

Social Sciences, 7 months ago

Sher Shah Suri, leader of the rival Sur dynasty, drives Humayun out of India and seizes power. Humayun takes refuge with the Safavid rulers in Persia, which serves to create a strong bond with the two dynasties. Create a timeline in chronological order showing the succession of all the great Mughal rulers in shaping the prosperous Mughal empire.

Physics, 7 months ago

Give reasons for : (a) When a carpet is beaten with a stick, dirt comes out of it. (b) It is difficult for a fireman to hold a hose which ejects large amount of water at high velocity.

Hindi, 7 months ago

4. लेखिका ने किसका उपचार किया?

Hindi, 1 year ago