First Derivative? 1st physics calculus class-help

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To find the velocity of a particle given its position function x = 7.8 + 9.2t - 2.1t^3, the first step is to differentiate the position function with respect to time t. The derivative is calculated using the power rule, resulting in v(t) = 9.2 - 6.3t^2. By substituting t = 3.5 seconds into the velocity equation, the velocity can be determined. The discussion highlights the importance of understanding differentiation and applying the correct formulas. Mastery of these concepts simplifies the process of finding derivatives in physics problems.
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the position of a particle on the x-axis is given:
x = 7.8 + 9.2t -2.1t^3

what is the velocity at t = 3.5 s ?

so i need to find the derivative of d/dt (7.8 + 9.2t -2.1t^3)

i'm completely lost on how to find it. thanks.
 
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Look up at the formula its simple plug in pro

d/dt(constatnt)=0
and
\frac{dx^n}{dt}=nx^{n-1}\frac{dx}{dt}
 
Thanks. That was really easy now that I see the correct formula. Differentiation by exponent.
 

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