Trig help (1 Viewer)

[YBK]

hey, just a simple question.


x = pie/3

evaluate
sec^2 x


The answer's 4, but I don't know how that came about.

Thanks

 

[Riviet]

sec²x=sec²(pi/3)
=1/cos²(pi/3)
=1/(1/2)²
=1/(1/4)
=4

 

[SoulSearcher]

sec² x = 1 / cos² x
x = pi/3
1 / cos² x
= 1 / (1/2)², as cos (pi/3) is equal to 1/2
= 1 / (1/4)
= 4

 

[YBK]

OMG, what made me think that pie/3 is 30degrees... soooo STUPID!!!!!!!

too much maths today is making me go crazy :S


thanks again

 

[Ennaybur]

AHHH lol i was about to say "duh, why is cos pi/3 = 1/2?" .. dw iv realised the error of my ways and seek a path to redemption

 

[icycloud]

Another way: sec²(pi/3) = tan²(pi/3) + 1 = 3 + 1 = 4