# trignonmetry

posted by .

6. Prove that tan λ cos^2 λ + sin^2λ/sin λ
= cos λ + sin λ

10. Prove that 1+tanθ/1-tanθ = sec^2θ+2tanθ/1-tan^2θ

17.Prove that sin^2w-cos^2w/tan w sin w + cos w tan w = cos w-cot w cos w

23. Find a counterexample to shows that the equation sec a – cos a = sin a sec a is not an identity.

• trignonmetry -

I think you mean
(tan*cos^2 + sin^2)/sin
= (sin*cos + sin^2)/sin
= sin(cos+sin)/sin
= cos+sin

I think you mean
(1+tan)/(1-tan)
= (1+tan)^2/(1-tan^2)
= (1+2tan+tan^2)/(1-tan^2)
= (sec^2+2tan)/(1-tan^2)

I think you mean
(sin^2 - cos^2)/(tan*sin+cos*tan)
= (sin-cos)(sin+cos)/(tan(sin+cos)
= (sin-cos)/tan
= sin*cot - cos*cot
= cos-cos*cot

always try simple values for counter-examples:
a=0: 1-1 =? 0 -- yes
a=pi: -1+1 =? 0 -- yes
a=pi/4: √2 - 1/√2 =? 1/√2*√2 NO!

## Similar Questions

1. ### Trig

Given: cos u = 3/5; 0 < u < pi/2 cos v = 5/13; 3pi/2 < v < 2pi Find: sin (v + u) cos (v - u) tan (v + u) First compute or list the cosine and sine of both u and v. Then use the combination rules sin (v + u) = sin u cos …
2. ### Math - Calculus

The identity below is significant because it relates 3 different kinds of products: a cross product and a dot product of 2 vectors on the left side, and the product of 2 real numbers on the right side. Prove the identity below. | a …
3. ### Physics

Which of the following equations describes the condition for observing the fourth bright fringe in Young's double-slit interference pattern?
4. ### trigo math

7. Prove that tan B sin B + cos B = sec B. 11. Prove that tanλ cos^2λ +sin^2λ/sinλ = cos λ + sin λ. 12. Prove that 1+tanθ/1+tanθ = sec^2θ+2tanθ/ 1-tan^2θ. 21. Prove that …
5. ### Trigonometry

1.Solve tan^2x + tan x – 1 = 0 for the principal value(s) to two decimal places. 6.Prove that tan y cos^2 y + sin^2y/sin y = cos y + sin y 10.Prove that 1+tanθ/1-tanθ = sec^2θ+2tanθ/1-tan^2θ 17.Prove that …
6. ### trigonometry help me

6.Prove that tan y cos^2 y + sin^2y/sin y = cos y + sin y 10.Prove that 1+tanθ/1-tanθ = sec^2θ+2tanθ/1-tan^2θ 17.Prove that sin^2w-cos^2w/tan w sin w + cos w tan w = cos w-cot w cos w 23.Find a counterexample …
7. ### precalculus

For each of the following determine whether or not it is an identity and prove your result. a. cos(x)sec(x)-sin^2(x)=cos^2(x) b. tan(x+(pi/4))= (tan(x)+1)/(1-tan(x)) c. (cos(x+y))/(cos(x-y))= (1-tan(x)tan(y))/(1+tan(x)tan(y)) d. (tan(x)+sin(x))/(1+cos(x))=tan(x) …
8. ### trig help much appreciated! :))

1. Find the complete exact solution of sin x = . 2. Solve cos 2x – 3sin x cos 2x = 0 for the principal value(s) to two decimal places. 3. Solve tan2 x + tan x – 1 = 0 for the principal value(s) to two decimal places. 4. Prove that …
9. ### Trigonometry desperate help, clueless girl here

2. solve cos 2x-3sin x cos 2x=0 for the principal values to two decimal places. 3. solve tan^2 + tan x-1= 0 for the principal values to two decimal places. 4. Prove that tan^2(x) -1 + cos^2(x) = tan^2(x) sin^2 (x). 5.Prove that tan(x) …
10. ### PRECALC

solve the equation 1. cos(θ) − sin(θ) = 1 2.2 cos(θ) tan(θ) + tan(θ) = 1 + 2 cos(θ) 3. sin(θ) cos(3θ) + cos(θ) sin(3θ) = 0 4. sin(2θ) cos(θ) − cos(2θ) sin(θ) …

More Similar Questions