JohhnyJOhhny
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- Joined
- Dec 5, 2020
- Messages
- 20
I dont even know where to start. I know the derivative of the equation is -3x^2 but that's all I got. Any hints?
So would the gradient just be -3?average rate of change ...
[MATH]\dfrac{y(b)-y(a)}{b-a}[/MATH]
Can someone confirm my answer?So would the gradient just be -3?
I plugged both the x variables into the derivative equation, and got the the points (-5, 15) and (-4,12) I then used the average rate of change formula and got -3.No, how did you get -3?
SI plugged both the x variables into the derivative equation, and got the the points (-5, 15) and (-4,12) I then used the average rate of change formula and got -3.
Should I not take the derivative?No, how did you get -3?
For the two points I got (-5, 126) and (-4, 64). I used the formula and then got -61. (I think you forgot the negative)If you put -5 into -3x^2, you get -75. I think you forgot to square it.
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Anyway, because you are finding the gradient between two points on the curve, you need to use the original equation, not the derivative. So the point (-5, -124) is one point. Find the other and then the gradient between them.
Remember, the derivative gives you a "rule" for working out the tangent at one given point. That's not want you are asked for here.
That should have been (-5, 126) and (-4, 65).For the two points I got (-5, 126) and (-4, 64). I used the formula and then got -61. (I think you forgot the negative)