# Math Help - trigo help

1. ## trigo help

Let angleA B C be angles of a triagnle ABC

if $cos^2\frac{B}{2}+cos^2\frac{C}{2}+cosA=3/2$

and $sinC + sinB = xsinA$

then find the value of $x$

2. Hello banku12
Originally Posted by banku12
Let angleA B C be angles of a triagnle ABC

if $cos^2\frac{B}{2}+cos^2\frac{C}{2}+cosA=3/2$

and $sinC + sinB = xsinA$

then find the value of $x$
Are you sure you have this question correct?

I assume that $x$ is supposed to have a constant value, but my spreadsheet calculations show that this is not so. For example:
$B = 40^o$ gives $C = 32.16462...^o, A = 107.83538^o$ and $x = 1.234469$
whereas
$B = 60^o$ gives $C = 16.7785^o, A = 103.2214^o$ and $x = 1.18614$

3. yes i am sure thats what is given in the question

4. Hello banku12
Originally Posted by banku12
yes i am sure thats what is given in the question
Sorry, but the question is simply wrong, if $x$ is supposed to have constant value.

Here's the Excel spreadsheet showing the calculations (with a slight improvement on the value of C in the second one).