# PRE CALC

posted by .

1. solve tan36 degrees- tan2degrees/ 1+tan36 degrees tan 2 degrees as a single function.

2. Find the exact value of sin (α-β) if sina=4/5 and cos β= -9/41 terminal side of α lies in I and terminal side of β lies in III

3. If cosx=1/12 and sinx > 0, find tan2x

thankyou!

• PRE CALC -

1. tan(36 - 2) = tan 34
2. sin ? = 4/5 --> cos ? = 3/5
cos ? = -9/41 --> sin ? = -40/41
sin(?-?) = sin?*cos? - cos?*sin? = ?
3. tan x = sqrt(143)
tan 2x = 2tanx/(1 - tan^2(x)) = ?

• PRE CALC -

how to calculate the value of tan36°

## Similar Questions

1. ### Math

If α and β are two angles in Quadrant II such that tan α= -1/2 and tan β = -2/3, find cos(α+β) Work: cos(α+β) = [ 1 - (tan α)(tan β) ] / [ 1 + (tan α)(tan β)] cos(α+β) …
2. ### Trig

prove sin(α+β)sin(α-β)=cos^2β-cos^2α please help... this is the only one I didn't understand out of all my homework...
3. ### physics (speed of plane by radar)

The radar stations A and B, separated by the distance a = 500 m, track the plane C by recording the angles α and β at 1-second intervals, If three successive readings are shown in the table,calculate the speed v of the plane …
4. ### PHYSICS

This is the same question as last time. "A plane is flying 25 degrees north of west at 190 km/h and encounters a wind from 15 degrees north of east at 45 km/h. What is the planes new velocity with respect to the ground in standard …
5. ### Trigonometry

The quadratic equation x^2−9x+10=0 has roots tanα and tanβ, where 0∘<α+β<180∘. What is the measure of α+β (in degrees)?
6. ### math

Complex numbers α and β satisfy αα¯=ββ¯=−17,α+β=7i. What is the value of αβ?
7. ### Pure Mathematics

4) The roots of the equation z^2+2z+4=0 are denoted by α and β. a) find α and β in the form re^iθ, giving the values of r and θ b) Using de Moivre's Theorem, show that α^3=β^3. c) find the exact …
8. ### trigonometry

In questions 2A, 2B, and 2C below, find the exact values using the given information: sin α = 1/6 with α between 0 and π/2 sin β = 3/5 with β between π/2 and π 2A. Find cos (α + β) 2B. Find …
9. ### Help- Precalc

Suppose that α is an angle such that tan α=(5/7) and sinα<0. ​Also, suppose that β is an angle such that cotβ=−3/5 and cscβ>0. Find the exact value of sine(α−β) -Direction …
10. ### Pre-calc

Hi Steve and Damon, if you're reading this, please take a look at my previous post because I had to apologize for my mistake. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ My Home Work Question: Suppose that α is an angle such that …

More Similar Questions