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Differentiate sin(x)*x^2

Notice that (sin(x))'= cos(x) and (x^2)' = 2x We use the product rule to differentiate, by noticing the expression is a product. so (fx gx)' = f'x gx + fx*g'x substituting in we get (sin(x)*x^2) = cos(x)*x^2...
DG
Answered by Drenusha G. • Maths tutor
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Find x when 2x^2-4x-6=0

Factorise 2x 2 -4x-6=0 2(x 2 -2-3)=0 -> 2(x+1)(x-3)=0 split factors up 2=0 , (x+1)=0 and (x-3)=0 x+1=0 -> x = -1 x-3=0 -> x = 3
IG
Answered by India G. • Maths tutor
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Find the point of intersection of the lines y=2x-7 and 4y-2=3x

Substitute y into 4y-2=3x 4(2x-7)-2=3x -> 8x-28-2=3x -> 8x-3x=28+2 -> 5x=30 -> x=30/5 -> x=6 subsitute x into y=2x-7 y=2(6)-7 -> y=12-7 -> y=5 Point = ( 6 , 5 )
IG
Answered by India G. • Maths tutor
4422 Views

How do I know when to use sin, cos or tan?

Check that your triangle is a right-angled triangle. Remember, you can only use pythagoras theorem or SOHCAHTOA on right-angled triangles. Label the sides O, H and A: opposite (the angle), hypotenuse (longes...
CS
Answered by Camilla S. • Maths tutor
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Why does the quadratic formula give solution to quadratic equation

Let the quadratic equation be of the form: ax 2 + bx + c = 0. Now by completing the square ( which can be done numeorous ways) get: a(x - b / 2a) 2 - a(b / 2a) 2 + c = 0. Then rearrange equation: a(x - b / 2...
TT
Answered by Tu T. • Maths tutor
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