Menu Close

If-sin-A-sin-B-a-and-cos-A-cos-B-b-then-cos-A-B-




Question Number 9218 by nazar last updated on 23/Nov/16
If sin A+sin B=a and cos A+cos B=b,  then cos (A+B)=
$$\mathrm{If}\:\mathrm{sin}\:{A}+\mathrm{sin}\:{B}={a}\:\mathrm{and}\:\mathrm{cos}\:{A}+\mathrm{cos}\:{B}={b}, \\ $$$$\mathrm{then}\:\mathrm{cos}\:\left({A}+{B}\right)= \\ $$
Commented by sandy_suhendra last updated on 24/Nov/16
cos(A+B) or cos(A−B) ?
$$\mathrm{cos}\left(\mathrm{A}+\mathrm{B}\right)\:\mathrm{or}\:\mathrm{cos}\left(\mathrm{A}−\mathrm{B}\right)\:? \\ $$

Leave a Reply

Your email address will not be published. Required fields are marked *