bewellplus.gsu.edu
ngoann4 ngoann4
  • 30-03-2015
  • Mathematics
Answered

Verify as an identity: cos(90°+x) = -sinx

I'm not sure how to go about this question

Verified Answer :

crisforp
crisforp crisforp
  • 30-03-2015

cos( a + b ) = cosa×cosb - sina×sinb ; 
a = 90 and b = x ;
But, cos90 = 0 and sin90 = 1;
cos( 90 + x ) = 0 × cosx - 1 × sinx = - sinx ;

Answer Link

Related Questions

10 Would I do 3length1width2height
What is 45 of 748
in this lesson using keywords is a way to help remember confusing words or concepts true or false
Select all that apply An informal essay is fiction is much more personal is meant to inform has a free structured style is entertaining rather than informative
How will the current economic state affect international business in the near future
2to the power of n 2 divided by 2 to the power of 5 2to the power of 2 what is N
What are the intercepts on a graph for y4x2
Base your answer to question 39 on the poem below and on your knowledge of social studies In The Quiet Land by Daw Aung San Suu Kyi In the Quiet Land no one can
Fiber optics is an example of a revolution in technology a intermodal b transportation c communications d Westernized
Which phrase should be placed in brackets