Search our library of homework questions

Top answers

All subjects

All levels

The potential difference in a circuit is 5V. There are two resistors connected in series of resistance 10 Ohms. Calculate the current I in the circuit.

Ohm's law states that V=IR ; where V is p.d., I is current and R is resistance.

Firstly the two resistors are in series so the total resistance is just the sum of the two resistanc...

Answered by Ryan S. • Physics tutor

4405 Views

Consider the functions f and g where f (x) = 3x − 5 and g (x) = x − 2 . (a) Find the inverse function, f^−1 . (b) Given that g^−1(x) = x + 2 , find (g^−1 o f )(x) . (c) Given also that (f^−1 o g)(x) = (x + 3)/3 , solve (f^−1 o g)(x) = (g^−1 o f)(x)

(a) Start with f(x)= 3x − 5; y=3x - 5, and switch x and y before rearanging to get y in terms of x again:

y=3x - 5

x=3y - 5

(x+5)/3=y

Therefore f^−1(x)=(x+5)/3

(b) Start...

Answered by Isobel B. • Maths tutor

18950 Views

5 students are in a maths class and 10 students are in a physics class. The mean mark of the maths class is 90 and the mean mark of the physics class is 85. Work out the mean mark of both classes.

To find the mean mark the formula is mean = ∑marks /number of students Therefore the mean for maths is 90 and so ∑marks = meannumber of students = 905 = 450 and the ∑marks for th...

Answered by Ryan S. • Maths tutor

3300 Views

Solve the differential equation: dy/dx = tan^3(x)sec^2(x)

dy/dx = tan³(x)sec²(x)

Integrate both sides ==> ∫dy= ∫ tan³(x)sec²(x) dx

Use the substitution u=tan(x)

And by different...

Answered by Ryan S. • Maths tutor

11587 Views

Describe the similarities and differences between simple diffusion, facilitated diffusion and active transport.

Simple diffusion, facilitated diffusion and active transport are three methods to transport various molecules across a membrane. Whilst similar in the overall effect, there are some major differences betw...

Answered by James G. • Biology tutor

72869 Views