Pre Cal

posted by .

could someone please tell me what the other angle identity of tan is? Thank you much!

"...other angle identity of tan x"?

in relation to which "other" ?

there are many identities dealing with the tangent.
The most important is probably

tan x = sin x/cos x

The Pythagorean Relationship would be

tan^2 x + 1 = sec^2 x

how about tan(2A) = 2tan A/(1-tan^2 A)

yes, i do know those, thank you. but my teacher told us that there is a specific identity for "the other angle". for example, the other angle identity of sinx = cos90-x. I believe the "other angle" identity for tanx is cot90-x but i'm not sure.

yes, you are right, tanx = cot(90-x)

if you are ever unsure about an identity like that pick an obscure angle such as 78.4º and test it with your calculator
tan 78.4 = 4.87162
cot(90-78.4)=cot 11.6º = 1/tan 11.6 = 4.87162

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. math

    could someone please tell me what the other angle identity is?
  2. Pre-Cal

    Perform the addition or subtraction. tanx - sec^2x/tanx tan^2(x)/tan(x) - sec^2x/tanx = tan^2x sec^2x / tanx then I use the identity 1+tan^2u=sec^2u I do not know what to do at this point.
  3. Pre-Cal

    1)tan 5 degrees + tan 25 degrees / 1 tan 5 degrees tan 25 degrees = sqrt 3 / 3 Am I correct?
  4. Trigonometry

    Find the exact value of tan(a-b) sin a = 4/5, -3pi/2<a<-pi; tan b = -sqrt2, pi/2<b<pi identity used is: tan(a-b)=(tan a-tan b)/1+tan a tan b simplify answer using radicals. (a is alpha, b is beta)
  5. precalc pre ap

    If theta is a rotation angle that terminates in quadrant ll and sin of theta is 5/13, find cos of theta and tan of theta. Use the first Pythagorean identity to solve for cos of theta and use quotient identity to solve for tan of theta.
  6. Pre-Calc (Prove the identity)

    Prove the identity. (show your work please) tan(x − π/4)= (tan x − 1)/(tan x + 1) Thank you!
  7. Pre-Calc Help!!!

    Prove the identity. (show your work please) tan(x − π/4)= (tan x − 1)/(tan x + 1) Thank you!
  8. Pre-Calculus

    This question has me stuck. Use the Pythagorean identity sin^2 Θ + cos^2 Θ = 1 to derive the other Pythagorean identities, 1 + tan^2 Θ = sec^2 Θ and 1 + cot^2 Θ = csc^2 Θ. Discuss how to remember these …
  9. Pre-Calculus

    A.Verify the identity. B.Determine if the identity is true for the given value of x. Explain. Sec(x) / tan(x) = tan(x) / [tan(x) – cos(x)],x = π I already solved A and I believe it's true; however, I need help with B.
  10. Pre-Calculus

    A.Verify the identity. B.Determine if the identity is true for the given value of x. Explain. [cot(x) – 1] / [cot(x) + 1] = [1 – tan(x)] / [1 + tan(x)], x = π/4 I solved A and I believe it's true; however, I need help with …

More Similar Questions