How would I go about finding the coordinates minimum point on the curve eg y = e^(x) - 9x -5?

In order to find the coordinates of the minimum point of any curve y = f(x), you must differentiate the equation of the curve with respect to x and then equate it to zero.In this case, the differential of the curve is: dy/dx = e^(x) - 9
Equating this to zero you find that e^x = 9.
Therefore x = ln(9)
Substituting this back int the original equation for the curve to find y: y= e^(ln(9)) - 9ln(9) - 5 , noticing that the e^ ln cancel out.
Thus, x = ln(9) and y = 9-5 - 9ln(9) = 4 - 9ln(9)

TR

Related Maths A Level answers

All answers ▸

How to integrate lnx by parts?


Find the gradient of the line with equation 2x + 5y = 7


A function f is defined by f(x) = x^3 - 3x^2 + 1. i) Write down f'(x). ii) Hence find the co-ordinates of the stationary points of the curve y=f(x).


A curve has equation y = e^x + 10sin(4x), find the value of the second derivative of this equation at the point x = pi/4.