Given that cosΘsinΘ=1/2, evaluate (cosΘ-sinΘ)^2

Question

anonymous · Answer

this is like in another language ! ugh i hate math -__-

anonymous · Answer

Lol yeah. Do you understand it though?

raden · Answer

let the value of (cosΘ-sinΘ)^2 = t, just expand it for left side gives
cos^2 Θ + sin^2 Θ - 2sinΘcosΘ = t
1 - 2*1/2 = t
1-1=t
so, t=0

anonymous · Answer

Wait, so where did the 1 - 2*1/2 = t  come from?

raden · Answer

u must know that identity of cos^2 Θ + sin^2 Θ = 1
and the value of sin Θcos Θ is given :)

anonymous · Answer

1) he multiplied it out
2) trig identities:  sin^u+cost^2u = 1
3) 1/2 comes from the quiestion itself

anonymous · Answer

OOOHH TRIG IDENTITIES
i FORGOT ABOUT THOSE!

anonymous · Answer

that should be sin^2u

raden · Answer

nopes, @ivan77 ... i see :)
study hard again @xxxtechmanxxx  :p

anonymous · Answer

Lawls, yeah, Pre-Calc isnt my strognest subject :P

raden · Answer

hehe... no problems, let's enjoying study in openstudy. because it's free :)

anonymous · Answer

openstudy lags so badly for me tht I cant stand it anymore.