Maths Help! (1 Viewer)

[Andy005]

https://drive.google.com/open?id=0B_RlXPQTW1cRUEhNMmR6RlB1X28

I need help with question c)

Any help would be greatly appreciated, Thanks.

 

[pikachu975]

a) tan30 = h/BD
BD = sqrt3 * h
tan45 = h/CD
CD = h

b) 2h^2 = x^2 - sqrt3 * hx

c) Divide everything by h and x
2h/x = x/h - sqrt3
2u = 1/u - sqrt3
2u^2 = 1 - u sqrt3
2u^2 + u sqrt3 - 1 = 0
u = (-sqrt3 +- sqrt(3-4(2)(-1)))/2(2)
u = (-sqrt3 +- sqrt11)/4
But u > 0 so don't take the negative case
u = (sqrt11 - sqrt3) / 4
h/x = (sqrt11 - sqrt3) / 4

 

[Andy005]

Thanks