P2 help.

Please Help with this.

Solve: cosx = sinx + 0.1 using the substitution obtained from letting tan1/2x = t, 0<x<360.

Thankyou for help. Will give rep.

If tan(x/2) = t, then you should be able to work out sin(x/2) and cos(x/2) in terms of t, and thus work out sin(x) and cos(x) in terms of t, then solve your equation for t and then get your x values.

tan(x/2)==t => sinx = 2t/(1+t); cosx = (1-t)/(1+t)

=> 1-t = 2t + 0.1(1+t)

3.1 t = 0.9

t = 0.29

x/2 = arctan 0.29 = 16.17, 106.17

x = 32.34, 212.34

tan(x/2)==t => sinx = 2t/(1+t); cosx = (1-t)/(1+t)

Just to briefly expand this (and correct it i think):

If t = tan(x/2) it follows that if we draw a right angled triangle with x/2 as one angle, and we call the opposite 't' and the adajcent '1' then the hypotenuse = root(1+t^2).

So sin(x/2) = t/(root(1+t^2)) and cos(x/2) = 1/(root(1+t^2)) as such sin(x) = 2sin(x/2)cos(x/2) = 2t/(1+t^2) and cos(x) = cos^2(x/2) - sin^2(x/2) = (1-t)/(1+t^2).

Shame it doesn;t put up your tag lines.

Have you read the Bible Code2 It too predicted the Twin Towers.

yes i have read it it is a bit interesting. shame it onlhy predicts stuff after it has happened.

It has predicted the some facts that are still to happen, Global war in 2006 centered on Israel and Palastinians. Both leaders are taking the book quite seriously. Rabin (sp?) assasination was also predicted and discussed with him indvance if it's occurance.

Did you catch the Bible Code programme on TV last night?