Rate of change

How do you do the following rate of change questions

when t = 1.2 for all the following questions:

1) y = 4/t + 4lnt

2) x = sin(t^2 +1) , y = cos(2t -3)

3) x = 1 / 1+2t , y = t / 1+t

4) q = 2e^-t/2.cos2t

5) x = e^2t.t^3(2-t)^4

Please could you explain the process as im quite lost. Thanks

e for 4) and 5) is the exponent

Quote:

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Originally Posted by dadon

How do you do the following rate of change questions

when t = 1.2 for all the following questions:

1) y = 4/t + 4lnt

2) x = sin(t^2 +1) , y = cos(2t -3)

3) x = 1 / 1+2t , y = t / 1+t

4) q = 2e^-t/2.cos2t

5) x = e^2t.t^3(2-t)^4

Please could you explain the process as im quite lost. Thanks

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The rate of change is the derivative with respect to time. So for 1):



so:

,

so when :



RonL

Thanks! On that question (1) I was confused about the 4lnt part. You make it seem so simple!