Saturday

February 28, 2015

February 28, 2015

Posted by **sarah** on Saturday, May 5, 2007 at 4:10pm.

Thanks!

cotx =1/tanx

cscx = 1/sinx

If you find it easier to conceptualize in degrees, realize that pi/4 radians is 45º and 3pi/4 is then 135º

If you know the CAST rule, it is easy to see that -pi/4 is in the fourth quadrant and tan(-pi/4) or tan(-45º) = -1

therefore cot(-pi/4) = -1

3pi/4 or 135º is in the second quadrant where the sine is positive.

so sin(3pi/4) = 1/(√2)

then csc(3pi/4) = √2

and 4csc(3pi/4) = 4√2

so the exact value of 3csc(3pi/4) - cot(-pi/4)

= 4√2 + 1

**Answer this Question**

**Related Questions**

Pre-Calculus - Find a numerical value of one trigonometric function of x if tanx...

drwls - My previous question: Verify that (secx/sinx)*(cotx/cscx)=cscx is an ...

trig - express this in sinx (1/ cscx + cotx )+ (1/cscx- cotx) i got 2sinx is ...

calculus - express in sinx 1 1 ---------- + -------- cscx + cotx cscx - cotx and...

Math - Im really struggling with these proving identities problems can somebody ...

Math - 1)A piano tuner uses a tuning fork. If middle C has a frequency of 264 ...

Math - Im really struggling with these proving identities problems can somebody ...

pre-calculus - given x = 1,110 degrees Find sinx, cosx, tanx, cotx, secx, cscx, ...

Pre-Calc - How do I solve this? My work has led me to a dead end. tan(45-x) + ...

Precalculus/Trig - I can't seem to prove these trig identities and would really ...