# identity

1. ### Verify the Identity

The instructions for this problem is to verify the identity. Thank you for your help! (sin3xcos5x-sinxcos7x) / (sinxsin7x+cos3xcos5x) = tan2x
2. ### proof of recursive identity

How can this be handled?
3. ### A Demonstration of an application of a half-angle identity

Dear My Math Forum Community: Express this as a single trigonometric function: (1 - cos 59.74 degrees)/sin 59.74 degrees The correct answer is: tan 29.87 degrees. Could someone please provide me with a step-by-step demonstration as to how the answer is arrived at? Thank you.:)
4. ### Bezout's Identity converse

Bezout's Identity: If d = gcd(m,n), there exist integers A and B st d=Am+Bn. (proved by Euclid's algorithm} 1) Is there a converse? 2) How would you express it? 3) How would you prove it?
5. ### Identity crisis 2

((cot (x))^2+1)/sin (x) expressed in terms of cos (x) is supposedly + or - 1/(1-(cos (x))^2)^(3/2). The graph of the left side is like a slimmer version of the csc function and not surprisingly is tangent to the minimum and maximum points of the sine function. The graph of 1/(1-(cos...
6. ### Identity crisis

From a College Algebra and Trigonometry textbook: An identity is an equation for which the solution set is the same as the domain of the variable. Accordingly, the equation (tan(x))^2*csc(x) = sin(x)/(1-(sin(x))^2) is supposed to be an identity with the right side expressed in terms in...
7. ### Verifying Trigonometric identity

Please help me figure out this problem. Cos(X-Y)/CosXCosY = 1 + TanXTanY I feel clueless. How do you verify this identity? Thanks!
8. ### Solve this Trig Identity

cot^2a = cos^2a + cota*cosa
9. ### Why my approach to prove this trigonometric identity does not work?

The problem is as follows: $\textrm{Prove:}$ $\sin 2\omega+\sin 2\phi+\sin 2\psi= 4 \sin\omega \sin\phi \sin\psi$ $\textrm{Given this condition:}$ $$\omega +\phi+ \psi= \pi$$ In my attempt to solve this problem I did what I felt obvious and that was to take the sine function to the whole...
10. ### Exponential identity

0 is the additive identity; i.e. 0+R=R 1 is the multiplicative identity; i.e. 1*R=R 0 is an "exponential inverse"; i.e. R^0=1 for Râ‰ 0 1 is an "exponential identity"; i.e. R^1=R 2 is a "universal identity"; i.e. 2+2=2*2=2^2
11. ### Prove the identity

Prove the identity Au.v = u.A^T v Note that "." in the equation means dot product. I know that I should write the dot products as products of matrices but I don't know how to do it. Thanks in advance :)
12. ### "Prove the following equation is an identity"

I've always struggled with these kinds of problems, since there's so many kinds of ways to do it. Often, whenever I try to solve and prove identities, I end up nowhere. :/ So some tips and advice would be awesome.
13. ### Does this identity belong with the circle functions or with the conic sections?

$$\alpha={\cot}^{-1 }(\cos\upsilon\tan{\sin}^{-1}(\frac{\sin\frac{\lambda}{ 2}}{ \sin\upsilon}))$$ The equation describes the relationship between 3 dihedral angles in 3D. It is expressed as: $$\alpha=f(\lambda)$$ To understand the angles, itâ€™s easiest to construct a unit sphere with...
14. ### A Video claims Euler's Identity finds prime pattern

I'm going to paraphrase the video, "e to the power of i multiplied by pi = i squared" "i to the power of 3 + 1 = i to the power of 4 = i to the power of 2 multiplied by i to the power of 2" " = -1 X -1 = 1 " "1st predecessor to the Formula of all Primes f(n)=2n+(n-5).i(n+1)+1" "Where n is...
15. ### Unopened Identity Access

The top represents how zeta is in ratio against the gamma identity, which is access in. The bottom represents how access in needs to use the transference medium state of the identity to find identity, and how it finds it. A more default state of opened identity access is where derivative 0 of...
16. ### Can anyone verify this identity?

cot(x) / csc^2(x) + csc(x)cot(x)-1 = sin(x)/(1+cos(x)) I tried using the fundamental identities but got stuck at some point or another. Any help is appreciated, thanks!
17. ### Tan(pi*x) identity

Is there any identity for $\tan(\pi z)$ in terms of closed analytical formulas removing the factor $\pi$ from the argument? I only know that \begin{eqnarray} \sin(\pi z)=\frac{\pi}{\Gamma(z)\Gamma(1-z)} \end{eqnarray} so could work as well with a formula for $\cos(\pi z)$ in the same way?
18. ### inverse trig identity

Is there an identity for the expression: [arccos (x/z) - arccos (y/z)] ? or can the expression be otherwise simplified?
19. ### Algebraic identity prove

Hi, I need to prove the following identity: I tried to go straight forward with the definition of (n choose k), but I got stuck. Do you know how can I prove this?
20. ### Arctan identity

Hey I'm trying to answer this without a calculator. Arctan(2+sqrt(3)) with calculator it is 75.