Thread: help rearranging this

i am wanting to rearrange to make h the subject h the subject and then b the subject

S= √(b2-h2)


can someone please help me

steve

Is your equation $\displaystyle S = \sqrt{b^2-h^2}$ ?

If so start by squaring both sides,

$\displaystyle S = \sqrt{b^2-h^2}$

$\displaystyle S^2 = b^2-h^2$

Then adding $\displaystyle h^2$ to both sides

$\displaystyle S^2+h^2 = b^2$

Finally taking the square root of both sides.

$\displaystyle \sqrt{S^2+h^2} = b$

$\displaystyle b = \sqrt{S^2+h^2} $

Do you follow?

Originally Posted by sugst893

i am wanting to rearrange to make h the subject h the subject and then b the subject

S= √(b2-h2)


can someone please help me

steve

I assume it's meant to be $\displaystyle \displaystyle S = \sqrt{b^2 - h^2}$ .... (Use h^2 NOT h2 to repesent powers).

Start by squaring both sides, then make $\displaystyle h^2$ the subject etc.

Originally Posted by pickslides

Is your equation $\displaystyle S = \sqrt{b^2-h^2}$ ?

If so start by squaring both sides,

$\displaystyle S = \sqrt{b^2-h^2}$

$\displaystyle S^2 = b^2-h^2$

Then adding $\displaystyle h^2$ to both sides

$\displaystyle S^2+h^2 = b^2$

Finally taking the square root of both sides.

$\displaystyle \sqrt{S^2+h^2} = b$

$\displaystyle b = \sqrt{S^2+h^2} $

Do you follow?

that is great thankyou so much if i want h the subject id do the same but divide doth sides by b is that correct

thats so great

Originally Posted by sugst893

that is great thankyou so much if i want h the subject id do the same but divide doth sides by b is that correct

thats so great

No. Post your working so that it can be reviewed.

ok so

first i would square both sides

then subtract s^2 from both sides

giving me h=sqrt{S^2-b^2}

stephen

No, if you want to make it this way, it's a little different.

$\displaystyle S = \sqrt{b^2-h^2}$

Square both sides:

$\displaystyle S^2 = b^2-h^2$

Now, Move b^2;

$\displaystyle S^2 - b^2 = -h^2$

You see that there is a minus sign? Multiply both sides by -1:

$\displaystyle -S^2 + b^2 = h^2$

Rearrange:

$\displaystyle b^2 - S^2= h^2$

Now, you take the square root.

$\displaystyle \sqrt{b^2 - S^2}= h$

$\displaystyle h = \sqrt{b^2 - S^2}$