Lv 31,050 points

# Isaiah

16, live in New Zealand.

• ### Is there an equation to solve the roots for a cubic?

Like the quadratic equation, but for a cubic.

• ### z=x+iy... help with complex please?

z=x+iy, find the values of x and y if... 1/z+2/(congugate)z=1+i

The answer is saying x=3/10, y=9/10... then it says solution x=0, y doesn't = 0, because of 1/z being undefined... i only managed to get x=0 when i tried doing this, i don't know what to do.

• ### z is the complex number...?

z is the complex number... (1+sqrt2+i) / (sqrt2-i)...

Find an expression in its simplest form for the exact value of the modulus of z.

• ### Help with this algebra question please?

"Solve for real x the inequality 1/x² ≥ 2/(x+k)², given that k is a positive constant."

I'm not 100% sure how to combat this, could you spare your time to help?

The answer says... (1-√2)k ≤ x ≤ (1+√2)k

Could you please show full steps? :l

• ### Need algebra help, I'm stuck?

Given x=(1-a)/(1+a) and y=(1-a^2)/(1+a^2) find an expression for a in terms of x, and an expression for y in terms of x.

I've worked out that a=(1-x)/(1+x) but I can't work out how to substitute that into Y without it just looking horrible, I can't work it out :L ---> the answer says 2x/(1+x^2) but I don't know how they're getting that.

• ### 6^(x+1)=3^x, how do you do this?

6^(x+1)=3^x... I get stuck

• ### 1 dimension collision?

A ball of mass m makes a head-on elastic collision with a stationary second ball of mass M

and rebounds with a speed equal to one-third its original speed. Show that the mass of the

second ball is equal to 2m

Ball X is dropped from height H and hits the ground with velocity V. Ball Y is thrown from the ground with velocity V at the same time ball X is dropped. Show that the two balls cross each other at 1/4H from ball X.

• ### Ball X is dropped from....?

Ball X is dropped from height H and hits the ground with velocity V. Ball Y is thrown from the ground with velocity V at the same time ball X is dropped. Show that the two balls cross each other at 1/4H from ball X.

Ae^kt - (A and k are constants, t is time)

when t is 3, the answer is 112486.

when t is 7, the answer is 131593

What is the answer when t is 10?

• ### y=x(x-1)(x+1) - need some help please?

Curve: y=x(x-1)(x+1)

Find the co-ordinates of the two points where the tangent to the curve is parallel to the x-axis :)

• ### y=x^3+px^2 - need help lol?

let y=x3+px2

determine p so that the gradient of the curve is 8 at the point x= -2

• ### Running 11km in a week, any tips?

I really need pointers on how I can keep myself going, I tend to stop and lose motivation when I do. I have to do it in less than 50 minutes also, I don't know if I could do it that fast.

• ### Need a lil bit of help?

Emma has an 8m long piece of rope that she uses to make the circumference of a circle.

C=2 pi r, A=pi r^2

1. Calculate the area of the circle, in terms of pi.

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George cuts x metres off the 8m rope and then makes the circumference of TWO circle, one from each piece of rope.

2.Write an expression for the sum of the areas of the two circles in its simplest form.

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You don't need to over explain your workings because I will understand what you're doing when you do it, thanks :).