Question

pada segitiga siku siku ABC berlaku sin A sin B =0,5, maka coS [A-B]

Answer 1

Answer:

1

Step-by-step explanation:

After translating to english the question is In the right angle triangle ABC , if sin A sin B = 0.5, find the value of cos (A-B)

we can take cos(A + B) = cos 90

Now we have the formula for

cos(A+B) = cos A cos B - sin A sin B

So cos A cos B -sin A sin B = cos 90

we know that cos 90 = 0

cos A cos B - sin A sin B = 0

  cos A cos B - 1/2 = 0

cos A cos B = 1/2

Substituting the values in cos(A - B) we have

  cos(A-B) = cos A cos B + sin A sin B

               = 1/2  + 1/2 = 1 + 1 / 2 = 2/2 = 1