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If y = (1+3x)^2, what is dy/dx?

A good approach to solve this is to use the chain rule of differentiation. The chain rule states: dy/dx= (dy/du)*(du/dx). In this case let u = 1+3x, so y = u^2. Then dy/du = 2u and du/dx = 3, so dy/dx = (2u)...
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Answered by Nishit B. • Maths tutor
10345 Views

If I have £730 in my bank account which has 2.5% compound interest per year, how much more money will be in there after two years?

AFTER 1 YEAR : interest = £730 x 0.025 = £18.25 Rotal money in my account = £730 + £18.25 = £748.25. AFTER 2 YEARS: interest = £748.25 x 0.025 = £18.706 Total money in my account = £766.96 (remember to round...
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Answered by Sally H. • Maths tutor
4536 Views

Given 4x+7y=25 and 2x+5y=17, identify x and y by solving the simultaneous equations

First thing we have to do is to eliminate one of the variables, either x or y (it doesn’t matter which one). In order to achieve that, we aim to have the same co-efficient (number in front of x or y) of a va...
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Answered by Andreas O. • Maths tutor
8477 Views

How would you differentiate ln(x^2+3x+5)?

Here we need to use the chain rule because we have a function (natural log) of another function (x^2+3x+5). Let u=x^2+3x+5, and differentiate lnu with respect to u, this gives us 1/u. Then we differentiate x...
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Answered by Oli H. • Maths tutor
25402 Views

Given 6x+2y=4 and 5x+y=8, solve the simultaneous equations to find x and y.

The key here is to eliminate one of the variables; it doesn't matter whether we start by trying to get rid of x or y we will arrive at the same solution. For us to eliminate either x or y it is easiest to fi...
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Answered by Rebecca M. • Maths tutor
8695 Views