







A trig identity 
20151028 

From Gail: verify sec(x) =cot(x)+tan(x)/csc(x), the csc(x) is under both the whole term cot(x) + tan(x) Answered by Penny Nom. 





A trig identity 
20130104 

From Tehmas: Prove sinC+sinD=2sin(C+D/2)cos(CD/2) Answered by Harley Weston. 





A trig identity 
20120108 

From Joe: Prove this Trig. Identity :
((cos2θ + sinθ1) / tanθ ) + sin2θ = cosθ Answered by Penny Nom. 





Tan(x+pi)tan(pix)=2tan(x). 
20110109 

From Steven: Verify the identity:
Tan(x+pi)tan(pix)=2tan(x) Answered by Penny Nom. 





A trig identity 
20100105 

From Christine: I need help with this whole paper here is one problem
csc^2xcot^2x/1sin^2x=sec^2x
by the ^2 i mean squared pleease Answered by Penny Nom. 





A trig identity 
20090710 

From sam: I need to prove:
tan x (cot x + tan x) = sec2 x
(the "sec2" is "sec squared")
I am totally stuck!!
Thanks! Answered by Stephen La Rocque and Harley Weston. 





Sec(2x) 
20081123 

From Evan: Prove that this is an identity...
sec2x = sec^2x / 2  sec^2x Answered by Harley Weston. 





A trig Identity 
20081113 

From Rebecca: Question from Rebecca, a student:
How do I prove:
1/sin@ csc@ 2sin@
________ + ______ = _____
1 + CSC@ 11/sin@ cos^@ Answered by Penny Nom. 





A trig identity 
20081103 

From Student: verify cos(2x)=(cot(x)tan(x))/(cot(x)+tan(x)) Answered by Penny Nom. 





TRIG IDENTITIES 
20080817 

From VINCE: HOW DO YOU SIMPLIFY THE FOLLOWING:
2sin3(theta)cos3(theta)?
Regards Answered by Harley Weston. 





cos3A=1/3 find cos6A 
20080515 

From mike: cos3A=1/3 find cos6A Answered by Penny Nom. 





(1tanx) / (1+tanx) = (1sin2x) / cos2x 
20080214 

From isaiah: i'm having trouble proving 1tanx / 1+tanx = 1sin2x / cos2x, can anyone help me from going crazy? Answered by Penny Nom. 





A trig identity 
20071110 

From James: I need to prove trig identities, and I can't figure this one out
1 + sinx  cosx 1  cosx
 = 
1 + sinx + cosx sinx
Answered by Chris Fisher. 





A trig identity 
20061214 

From Zamira: i need help with this proof: ((cot(x)tan(x))/ cot(x) + tan(x)) = cos (x) Answered by Penny Nom. 





Sin 2x / 1Cos 2x = 2 Csc 2x  Tan x 
20061206 

From Mark: I need to prove the following: Sin 2x / 1Cos 2x = 2 Csc 2x  Tan x Answered by Steve La Rocque. 





tan1/2x + cot1/2x = 2cscx 
20061104 

From Jazmin: Prove tan1/2x + cot1/2x = 2cscx Answered by Penny Nom. 





A trig identity 
20060604 

From Courtney: Show that this equation is an identity:
(sin x + sin 2X)/(cos x  cos 2x) = cot(x/2) Answered by Stephen La Rocque. 





A trig identity 
20060328 

From Iqbal: Could you please prove,
[tan(x)sin(x)]/sin^{3}(x)=sec(x)/[1+cos(x)]
Answered by Stephen La Rocque. 





A pair of trig equations 
20051205 

From Kevin:
I am trying to solve for A and B but haven't been able to find a trig identity that will help me.
1.414 = .5cosA + cosB
.5 = .5sinA  sinB
how do I solve this?
Answered by Penny Nom. 





A trig identity 
20050306 

From Patrick: im trying to verify this
identity:
sin(x)+sin(5x)
 = tan(3x)
cos(x)+cos(5x)
Answered by Chris Fisher. 





A trig identity 
20030520 

From Patty: Please help with the following
1/ tanx + cotx = sinxcosx Answered by Penny Nom. 





A trig identity 
20030222 

From Ron: We have spent hours trying to solve the following identity without success. Can you give us some hints as to how it is done?
1 + tan(x) tan(2x) = tan(2x) cot(x) 1 Answered by Penny Nom. 





An identity? 
20021027 

From Jenna: I can't prove
1sinQ 1  = tanQ +  1+sinQ cosQ
Answered by Penny Nom. 





An identity(?) 
20020502 

From A student: prove identity sin^{ 2}x/1sinx= secx+1/secx
Answered by Paul Betts. 





A trigonometric identity 
20020322 

From Debby: I am stuck on a problem and wondering if you can help?? It is: Prove the following: sec^{2}(X)+csc^{2}(X) = sec^{2}(X)csc^{2}(X) Answered by Harley Weston. 





A trig identity 
20010727 

From Jeff: prove this identity and show steps tan(x/2+pi/4)=secx+tanx Answered by Harley Weston. 





Trig identity crisis 
20001129 

From Rhiannon: I have tried many times to find the answer to these problems but I can't I am in grade 12  tan(x)=csc2(x)cot2(x)
 cos(x)/csc(x)2sin(x)=tan(x)/1tan(x)
 cos(x)[ tan^{2}(x)11]/cos^{2}(x)+sin^{2}(x)=sec(x)
Answered by Harley Weston. 





A trigonmetric identity 
20000515 

From Caitlin: My name is Caitlin and my question is from 11th grade math and I'm a student my question is I need to solve this identity : cos x csc x  sin x sec x = 2 cot 2x Answered by Paul Betts. 





A trig identiry 
20000223 

From Ashlee: I am having problems doing this problem. Can you help? Verify the identity: (1+cot^{2}X)(1cos2X)=2 Answered by Harley Weston. 





A trig identity 
20000217 

From Eric:
Question: How do I solve this problem? sin3x cos3x _____  _____ = 2 sinx cosx Answered by Chris Fisher. 





Proving a trigonometric identitiy 
19991217 

From Ryan: I need to figure out how to prove that sec^{2}x + csc^{2}x = sec^{2}x csc^{2}x. I am not sure where to start out with it and whether I should use reciprocal, quotient, or pythagorean. Answered by Penny Nom. 





A trig problem 
19990603 

From Stu Barnes: cos(theta) / 1+ sin(theta)=sec(theta)tan(theta) I've being having trouble with this one on my correspondance course. Answered by Harley Weston. 





A trig identity 
19960311 

From Azmat Hussain: Is there an easier/another way to prove the trig identity cos(a+b) = cos(a)cos(b)sin(a)sin(b)? Answered by Penny Nom. 





Trig identities 
19951130 

From Azmat: Why do we work on the two sides of a trig identity separately? Answered by Harley Weston. 

