Tuesday
March 28, 2017

Post a New Question

Posted by on .

given that sin(a+b)= 56/65, cos(a+b)-33/65, cos(b)=-12/13 and pi/2<b<pi
Find:
sin(a)?
cos(a)?
tan(a)?

  • trig - ,

    Assuming that cos(a+b) = -33/65

    sin(a+b) = sin a cos b + cos a sin b
    cos(a+b) = cos a cos b - sin a sin b

    -12/13 sin a + 5/13 cos a = 56/65
    5/13 sin a + 12/13 cos a = -33/65

    Multiply by 5 to clear denominators:

    -60 sin a + 25 cos a = 56
    25 sin a + 60 cos a = -33

    sin a = -507/845
    cos a = 676/845
    so,
    tan a = -507/676

Answer This Question

First Name:
School Subject:
Answer:

Related Questions

More Related Questions

Post a New Question