Proof of sen² 25º + cos² 45º + sen² 65º = 3/2

Fanekaz · Nov 1, 2009

Homework Statement

Show that sen² 25º + cos² 45º + sen² 65º = 3/2

cos 45º= 1

I get confused with the ² on the cos and sen...

tiny-tim · Nov 1, 2009

Hi Fanekaz!

(btw, it's sin, not sen

)

Fanekaz said:

I get confused with the ² on the cos and sen...

It just means that the whole thing is squared …

so sin²x means (sinx)² …

(pronounce it "sine squared of x")

it saves writing brackets.