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i) Using implicit differentiation find dy/dx for x^2 + y^2 = 4 ii) At what points is the tangent to the curve parallel to the y axis iii) Given the line y=x+c only intersects the circle once find c given that c is positive.

I don't know how effectively I can communicate this answer via text without the whiteboard but I'll try. i) First implicitly differentiate with respect to x: 2x + 2y * dy/dx = 0. Rearranging gives dy/dx = -x...
JD
Answered by James D. • Maths tutor
5607 Views

Solve the simultaneous equations, 2x+y-5=0 and x^2-y^2=3

2x+y-5=0, y=5-2x (put into second equation) x 2 -y 2 =3, substituting in we get, x 2 -(5-2x) 2 =3, expand, x 2 -(25+4x 2 -20x)=3, simplify, x 2 -25-4x 2 +20x=3, 0=3x 2 -20x+28, put into brackets by seperatin...
JS
Answered by Joshua S. • Maths tutor
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2a + 6b = 24, 3a + b = 20

a + 3b = 12, a = 12 - 3b 3(12-3b) + b = 20 36-9b + b = 20 36-8b = 20 8b = 16 b = 2 2a + 12 = 24 2a = 12 a = 6
AC
Answered by Ailsa C. • Maths tutor
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Factorise x^2 - 8x - 20

x^2 - 8x - 20 (x - 10)(x+2) (Explanation and helping understanding) Remember the last 2 numbers must multiply to equal the last number in the question and add together to equal the middle number. See that th...
CS
Answered by Christian S. • Maths tutor
5191 Views

Expand 5(2x-6)

To begin answering this question create a small grid put 5 on the left hand side and put 2x and -6 seperately at the top of the grid then you can multiply 5 by 2x to gain 10x and multiply 5 by -6 to gain -30...
ZY
Answered by Zaarah Y. • Maths tutor
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