<span>NCn is always equal to 1. </span>
Yes because the unit rate would be 1:2 and that's the rate of change in which 3:5 has.
HOPE IT HELPS!!
<h2>
<u>Sol</u><u>ution</u><u>:</u></h2>
Equation: x² + 10x + 21
<u>Step</u><u> </u><u>1</u><u>:</u> Find two numbers that can add up to 10 and be multiplied to 21. We have: 7 & 3, in the sense that 7+3=10, and 7×3=21. Replacing 10 with 7+3, the equation is now → x² + 7x + 3x + 21
<u>Step</u><u> </u><u>2</u><u>:</u> Get the new equation bracketed → (x² + 7x) (+3x + 21)
<u>Step</u><u> </u><u>3</u><u>:</u> Use 'x' in the equation. For the first part, we have 'x'. x² = x × x so, bring out one x out side the bracket, divide 7x by = 7 → x (x +7). Do the same for the second part by dividing 21 by 3 = 7, and then bringing out 3 from the bracket → 3 (x + 7).
Bringing everything together, we have: x(x+7) +3(x+7) → (x+3) (x+7)
<h3>
<u>Final</u><u> </u><u>ans</u><u>wer</u><u>:</u></h3>
(x+3) (x+7)
<h3 />
(7x^2-3x)+4x^2
7x^2+4x^2-3x
11x^2-3x
Answer: 11x^2-3x.
You just combine like terms.
For polar form you need to find the modulus (length of the vector) and the argument (angle of the vector) and present in form rcis(Arg) or re^Argi
start with the modulus r=sqrt(a^2 +b^2)
=sqrt(-2^2 +2^2)
= sqrt(4+4)
=sqrt(8)
=2sqrt(2)
next the argument, firstly arg=tan(b/a)
= tan(2/2)
=tan(1)
=pi/4 . (exact values table)
Now consider the quadrant the complex number is in, as it is (-2,2) it is in the second quadrant and as such your Arg value is:
Arg=pi-arg
= pi-pi/4
= 3pi/4
add it all together and your complex number in polar form is:
2sqrt2cis(3pi/4)
note: cis is short hand for cos(x)+isin(x), it is possible your tutor would rather you use the complex exponential form which is simply re^Argi and your answer would look like:
2sqrt2e^(3pi/4)i
Also notice the difference between arg and Arg as this often slips students up and always present Arg in prinicple argument form ie -pi<Arg<pi
Hopefully this has been clear enough and good luck
