The variables x and y are related by y = 5^x. How do I find the value of x when y is set to 15?

15 = 5^x, we can easily solve this equation by using logs on either side which will give us: log15 = x log 5. Then by solving this for x, we get the result of 1.68 to two decimal places.

AB

Related Maths A Level answers

All answers ▸

What is a logarithm?


Integrate 5(x + 2)/(x + 1)(x + 6) with respect to x


Express 6cos(2x)+sin(x) in terms of sin(x). Hence solve the equation 6cos(2x) + sin(x) = 0, for 0° <= x <= 360°.


A straight line passes through the point (2,1) and has a gradient of 3. Find the co-ordinates where the line crosses the x and y axes