Question

true or false??

sec30°cos60° = 1

Answer 1

true

Answer 2

secant is the same as just 1/cosine, so you really have:

cos(60)/cos(30)=1. So if you multiply both sides by cos(30) you'll get:

cos(60)=cos(30)

is this true or not? Remember, these are circular functions, so it's possible that even though they have different angles in them, they can still be equal for their outputs.

Answer 3

sec30 = 2\sqrt3
cos 60= 1\2
so when we multiply it
\[\frac{ 2 }{ \sqrt{3} }\times \frac{ 1 }{ 2 }= 1\sqrt 3
it is not true
because left hand side is not equal to right hand side

Answer 4

remember, on the unit circle cosine tells you the x-value of a triangle made by rotating by that many degrees.

So I've drawn the triangles made by going 30 and 60 degrees. Are their x-coordinates the same? If they are, it's true.

Answer 5

hint: @kc_kennylau is wrong this time.