# Math Help - Decimal search for roots

1. ## Decimal search for roots

a) show praphically that the equation 3cos(x) = x^2+1 has exactly one positive real root

the problem here is that I have no idea how to draw the graph etc.

b) find an interval for this root in the form (a/10 , (a+1)/10 ) where a is an integer; theres a note saying to make sure that the calculator is in radians mode

c) calculate this root to 1dp.

I dont know whether parts b) and c) would ause me trouble, it's just that without part a) I can't really move on.

any help will be appreciated, thanks

2. ## Re: Decimal search for roots

Surely you can graph y = 3cos(x) and y = x^2 + 1 and show they only intersect once in the domain $\displaystyle x > 0$...

3. ## Re: Decimal search for roots

that's so true.. I haven't thought of that, thanks!