Recent content by Dramacon

If a car is pushing a bus (and the two both move in the direction of the car), I understand that the amount of force with which the car pushes against the bus is equal to the force the bus pushes back on the car. What I don't understand is why the car moves. Is it going forward with the same...

Ah, I see! Thank you! :)

Homework Statement I'd always used the 2nd derivative test for the nature of stationary points. But I came across this equation in one of my exercises, for which the test doesn't seem to work at all. Find the stationary points of: y=(x^2-1)4, stating the nature of each. Homework...

Haha, that was simpler than I thought! :D Thank you so much!

Hello there! I understand the product rule and how/why it works, and the proof makes sense, but just out of curiosity, why would it be incorrect on a mathematical/application level to say that d/dx f(x)g(x) = f'(x)g'(x) I know that it's wrong, and the product rule is the one that we're...

Ah, I see! :) Thank you! This makes so much more sense now.

Or do you mean increasing from one stage to the next?

So when a line is at more than 45 degrees, you mean?

Homework Statement f(x)= 3+6x-2x^3 (a) Determine the values of x for which the graph of f has positive gradient (b) Find the values of x for which the graph of f has increasing gradient Homework Equations I had originally thought the two terms meant the same thing, but when I checked the...

the derivative of a function is its gradient, which is also defined as rise/run. In trig, rise/run = tanθ! therefore tan45°=1 And then just use one of the aforementioned methods of substitution into y'. :)

Stationary Points and finding variables? :) Homework Statement The curve with the equation y=ax^2 + bx+c has a stationary point at (1,2). When x=0, the slope of the curve is 45 degrees. Find a, b, c. Homework Equations I'm not sure how to create an equation that involves the 45...

Homework Statement As the result of a survey, the marketing director of a company found that the revenue, $R, from selling n produced items at $P is given by the rule R=30P-2P^2 Find dR/dP and explain what it means Homework Equations I've found the dR/dP, however, I'm unsure of what this...

Homework Statement Find the perpendicular distance between y=2x-1 and y=2x - 8/3 2. The attempt at a solution The first equation hits the y-axis at -1 and the other at -8/3, which means the vertical (y axis) distance between them is 5/3, but to use trig, I need another piece of...

This is just me being pedantic :)