Top answers

What is 17 multiplied by 120?

Using the grid method, we know this is equal to (10 100) + (10 20) + (7 100) + (7 20) = 1000+200+700+140 = 2040
CD
Answered by Cam D. • Maths tutor
5179 Views

How do I integrate and differentiate 1/(x^2)?

1/( x 2 ) can be written as x -2 We know that to differentiate you need to multiply by the value of the old power and minus 1 from it. This means dy/dx of y= x -2 is -2 x -3 =-2/(x 3 ) To integrate you add o...
JG
Answered by Judy G. • Maths tutor
4710 Views

what is 64 to the power of 2/3?

If a number is to the power of 2/3, you should think of it as to the power of 1/3 (so CUBE-rooted), and then being to the power of 2 (so squared). So here, the cube root of 64 is 4, because 4x4x4=64. Then yo...
SO
Answered by Stephanie O. • Maths tutor
94969 Views

How do I know when to use Sine, Cosine and Tangent

The easy way to remember these uses the acronym SOH-CAH-TOA The function to use depends on the sides of the triangle you know in the problem. With right angled triangles each side has a name: the hypotenuse ...
JG
Answered by Judy G. • Maths tutor
16807 Views

Let w, z be complex numbers. Show that |wz|=|w||z|, and using the fact that x=|x|e^{arg(x)i}, show further that arg(wz)=arg(w)+arg(z) where |.| is the absolute value and arg(.) is the angle (in polar coordinates). Hence, find all solutions to x^n=1 .

Put w=a+bi, z=c+di where a, b, c, d are real, and i 2 =-1. Then |wz| 2 =|(a+bi)(c+di)| 2 =|ac-bd+(ad+cb)i| 2 =(ac) 2 +(bd) 2 -2bcd+(ad) 2 +(cb) 2 +2abcd=(ac) 2 +(bd) 2 +(ad) 2 +(cb) 2 =(a 2 +b 2 )(c 2 +d 2 )...
JK
Answered by Jihoon K. • Maths tutor
8314 Views