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Find dy/dx in terms of t of the parametric equations x=4e^-2t, y=4 - 2e^2t

x=4e^-2t, y=4-2e^2t

dy/dx = dy/dt * dt/dx

dy/dt = -4e^2t

dx/dt = -8e^-2t dt/dx = -1/8 * e^2t

dy/dx = (-4e^2t

Answered by Josh M. • Maths tutor

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Mike, Sam and James play football. Mike scores 8 more goals than James. Sam scores 5 more goals than Mike. Altogether they score 72 goals. How many did Sam score?

Let James = x

Mike = x+8

Sam = Mike+5 = (x+8)+5 = x+13

Altogether: James + Mike + Sam = 72

Therefore, x + (x+8) + (x+13) = 72

Now solve for x: 3x + 21 = 72

Bring...

Answered by Joshua R. • Maths tutor

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How to use the quadratic formula, using the following equation: x^2 + 3x - 4

To begin you must identify the co-efficients of each x term, essentially what number comes before x², x and the integer value.

a = 1, b = 3, c = -4 . We then substitute these values int...

Answered by Oliver B. • Maths tutor

2988 Views

I know the formula, but I don't understand it.

A thorough understanding of all the mathematical formulas prescribed in the subject specification is crucial for your survival in the no-mans-land of the maths exam, where your examiner tries his best to ...

Answered by Le L. • Maths tutor

3327 Views

Bill buys 8 identical cricket balls. The total cost is £169.04 Work out the total cost of 19 of these cricket balls. (Calculator allowed).

Start by identifying the cost of one cricket ball: £169.04 ÷ 8 = £21.13 Next multiply this by the number of cricket balls he wants to buy: £21.13 x 19 = 401.47 The total cost of 19 cricket balls is £401.4...

Answered by George J. • Maths tutor

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