misc revision q's that i need help with coz i'm dumb! (1 Viewer)

[nomz]

Hi!
Can anyone please help me with any of these questions?

1)Solve √( x +1) > 2 / ((x -2) + 2)

2)A car at point A is travelling due north at 100 km / hr. Towns B and C are at bearings 330T and 030T respectively from A. 1 hour later the car is at point D and the towns are at bearings 300T and 045T respectively. Find the exact distance between the two towns.

3)Solve (using t = tan A/2) 3cosA + 4sinA = 1. 0<A<360

4)Triangle ABC (see attachment) is isosceles with BA = BC, <ABC= 20, <CAF= 50, <ACD= 20 and <DCE= 40. Find <CEF.

Thanks heaps !

 

[AreYouAlright?]

SOLn

I think some of your math's question for the inequality with an unknown on the denominator did not display properly - if you meant..

x + 1 > 2
...........----
...........(x-2)+2

Then SOLn is x > 1 or -2 < x < 0

I couldn't quite be bothered working the other one's out now... maybe later, anyone feel free to correct me if i am wrong.. i probably am

 

[AreYouAlright?]

SOLn t = tan A/2

I got tan A = 2 + root 3 or 2 - root 3
so.... A = 75 deg. or 15 deg.

Could be totally wrong tho...

3cosA + 4sinA = 1

let t = tan A/2

3 ( [1-t^2]/[1+t^2]) + 4 ( 2t / [1+t^2]) = 1

3 - 3t^2 + 8t = 1 + t^2
4t^2 - 8t -2 = 0

t = 8 + or - 4root6 / 8

A/2 = [2+root6]/2 or [2-root6]/2

so A would be double...
giving tan A as 2 + root 3 or 2 - root 3

 

[nomz]

thanks heaps for you're reply- i had no idea how to even start that question coz i was away when we did trig equations and my teacher couldn't be bothered to show me how to do them !

 

[AreYouAlright?]

Anytime..

That's okay, lol i hope those answers are right... lol but yeah not being there when you started trig equations would just about do it to you..