# Quadratics a level maths help!

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#1
pls do these two questions for me. Do it on paper n take a photo of the solutions and send them to me. Very urgent!
0
4 years ago
#2
(Original post by Yoora3)
pls do these two questions for me. Do it on paper n take a photo of the solutions and send them to me. Very urgent!
Eh, no. What's your problem? What's confusing you? What have you tried?
1
4 years ago
#3
Have you even tried them? What's the problem?

edit: lol beat me to it ^
1
#4
I did try. But i don't have the answers. And am weak in quadratics. For the first question i don't know how to sketch. For the second one, i don't understand part (ii)
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#5
(Original post by Parallex)
Have you even tried them? What's the problem?

edit: lol beat me to it ^
I don't know how to do it at all.
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4 years ago
#6
(Original post by Yoora3)
I did try. But i don't have the answers. And am weak in quadratics. For the first question i don't know how to sketch. For the second one, i don't understand part (ii)
If you want us to check your answers, then put your answer up and we'll check it. You don't need to sketch for the first part, you're just meant to interpret geometrically the solutions to those two curves. hint: think about intersections.

The domain of f^(-1)(x) is the range of f(x). f(x) is a quadratic and has a minimum point, see if you can work out the range of that.
1
4 years ago
#7
(Original post by Yoora3)
I did try. But i don't have the answers. And am weak in quadratics. For the first question i don't know how to sketch. For the second one, i don't understand part (ii)
To sketch, factorise the quadratic to find the roots then just plot the axis intersections and draw the curve from them. I'm sure you don't have a problem drawing a y=mx+c line.

for 2ii) it'd be a good start to find the range of . You should know the relationship between and geometrically -which will help you find the domain of the inverse function.
0
4 years ago
#8
Have you tried it yourself at least ?

Posted from TSR Mobile
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#9
(Original post by Zacken)
If you want us to check your answers, then put your answer up and we'll check it. You don't need to sketch for the first part, you're just meant to interpret geometrically the solutions to those two curves. hint: think about intersections.

The domain of f^(-1)(x) is the range of f(x). f(x) is a quadratic and has a minimum point, see if you can work out the range of that.
0
4 years ago
#10
(Original post by Yoora3)
All you have to do for (i) is just show that the discriminant of the quadratic you are left with is smaller than 0.

The completing the square bit looks good, well done!
0
4 years ago
#11
(Original post by Yoora3)
For part (I) I think you should do b^2-4ac and it should be less that 0 to prove that it has no real roots.

Posted from TSR Mobile
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#12
(Original post by Zacken)
All you have to do for (i) is just show that the discriminant of the quadratic you are left with is smaller than 0.

The completing the square bit looks good, well done!
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#13
Is the sketch good for question 1?? The solution is (3,2) - - - the answer i got.
0
4 years ago
#14
(Original post by Yoora3)
I'm not sure what the sketch is for?
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4 years ago
#15
Damn, question 3 looks tough!
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