# Trigonometry

posted by .

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 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.

• Trigonometry -

1.
Some students like to look at these types the following way:
let tanx = y, to get
y^2 + y - 1 = 0
by formula ...
y = (-1 ± √5)/2
so tanx = (-1 ± √5)/2
x = 31.72° or 211.72°

or tanx = (-1 - √5)/2
x = 121.72° or 301.72°

#6, 10, 17,
establish correct order of operation, by using brackets.

#23
just pick any angle you want and use your calculator
or pick a = 30°, (you should know the trig values for 30°)

## Similar Questions

1. ### math

Prove the following identities: a) (cosec θ + cotθ)(cosecθ - cotθ) = cotθtanθ b) 2/(1 + sinθ) + 1/(1- sinθ) = (3sec^2)θ - tanθcosecθ I basically just have to prove Left HandSide …
2. ### pre-calc help !!!!!!!

1) cscθsinθ-sin^2θ 2)sinθcscθ/tanθ 3)secθ/cotθ+tanθ 4)(1-cosθ)(1+cosθ)
3. ### math trigono

1. If tanθ = –√3 , what is the value of cot ?
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. ### trignonmetry

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 …
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. ### 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 …
8. ### 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) …
9. ### Trigonometry

Could someone please help me with the following q's I'm having some trouble: 1.) cot θ (theta) = 0.791, find sec θ and tan θ 2.) tan θ = 9/40, what is the value sin^2θ + cos^2θ
10. ### Trig

Verify the given equations: ____1______ + ____1_______ = -2 tanθ tanθ – secθ tanθ + secθ 1 – sinθ = sec2θ – 2 secθ tan θ + tan2θ 1 + sinθ

More Similar Questions