# Multipul questions

• Mar 3rd 2008, 01:17 PM
salerk
Multipul questions
To start, If possable I dont want any answers just methoulds or keywords to google in order to gain the nessary information to solve the problems.

Thing is our math/physics tutor got in a car accident a few months ago so his classes where called off, so we have been given our math test and well ive got no clue on some of this because we just did not get taught it.

Ive managed to work out the other 21 questions but these 4 just have me stumped big time, once again please if possable just an explination of how to do them would be great. Im not here just to be told an answer, lol.

Simplify the expression to $4a^5 a^6 / (4a^4)^2$ to $(m / n) a^5$where $m/n$is a factorisation expressed in its lowerst form

Express 7 SQRoot 13 in the form of SQroot n

Find the Angle (in degrees) between the Vectors: (3 -7) and (-8 -9) ***Dont know if this changes howthe question is worked out but the -7 is ment to be under the 3 as is the -9 ment to be under -8)

And the last question:
Solve $-2sin x^0 +3 =4$
• Mar 3rd 2008, 01:30 PM
TKHunny

$a^{m}*a^{n} = a^{m+n}$

$a^{m}/a^{n} = a^{m-n}$

$[a^{m}]^{n} = a^{mn}$

This is also good for the square root question.

For example:

$7\sqrt{1} = \sqrt{7^{2}} = \sqrt{49}$

As far as the angle between the vectors...

Have you met the "Vector Inner Product"? Perhaps we should use the method of slopes? There are a few ways to go about it.

On the last, is the exponent "0" just a typo? Perhaps you meant $x_{0}$? In any case, just solve it.

-2sin(x) + 3 = 4

-2sin(x) = 1

sin(x) = -1/2

You should know values of x that have this sine value. Think "Quadrant" before you believe you are done.
• Mar 3rd 2008, 01:33 PM
xifentoozlerix
$
\frac{{4a^5 a^6 }}
{{\left( {4a^4 } \right)^2 }} = \frac{{4a^6 }}
{{16a^8 }}a^5 = \frac{1}
{{4a^2 }}a^5 = \frac{{a^{ - 2} }}
{4}a^5

$

$
7\sqrt {13} = \sqrt {49} \cdot \sqrt {13} = \sqrt {49 \cdot 13} = \sqrt {637}

$
• Mar 3rd 2008, 02:29 PM
salerk
Thanks for your help, Expect Ill be back thatr was simply fantastic advice and ended up geting 70% so once again thank you