20
the co- in cosine means sine of the complementary angle.
If cos(90-A) = cos90cosA + sin90sinA = sinA
1) If the Sin(70 degrees)= Cos(A), what must A be?
2) Why is the Sine of 10 degrees the same as the Cosine of 80 degrees?
2 answers
cos 20
they are the same because they are complementary angles.
70 + 20 = 90
80 + 10 = 90
they are the same because they are complementary angles.
70 + 20 = 90
80 + 10 = 90
1 answer