What is the exact value of cos 40 degrees cos 50 degrees minus sin 40 degrees sin 50 degrees
do you know the formula
cos(A+b) = cosAcosB - sinAsinB
now compare it with your
cos 40 degrees cos 50 degrees minus sin 40 degrees sin 50 degrees
Yes, I am familiar with the formula you mentioned.
The given expression: cos 40 degrees cos 50 degrees minus sin 40 degrees sin 50 degrees can be rewritten as: cos(40 degrees + 50 degrees), which follows the formula cos(A + B) = cosAcosB - sinAsinB.
Now, let's substitute the values into the formula:
cos(40 degrees + 50 degrees) = cos(90 degrees).
As we know, the cosine of 90 degrees is 0. Therefore, the exact value of cos 40 degrees cos 50 degrees minus sin 40 degrees sin 50 degrees is 0.