Compute on casio fx-82MS 8cos2(0.6) + 3

I think you have to do the derivative by hand  

i(t) = 4 sin 2t + 3t, when t = 0.6

i'(t)=4cos(2t)*2+3

i'(t)=8cos(2t)+3

i'(0.6)=8cos(2*0.6)+3

Make sue your calc is set to radians.

8*cos(2*0.6)+3=

that should give you the correct answer

$${\mathtt{8}}{\mathtt{\,\times\,}}\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{cos}}{\left({\frac{{\mathtt{2}}{\mathtt{\,\times\,}}{\mathtt{0.6}}{\mathtt{\,\times\,}}{\mathtt{180}}}{{\mathtt{\pi}}}}\right)}{\mathtt{\,\small\textbf+\,}}{\mathtt{3}} = {\mathtt{5.898\: \!862\: \!035\: \!816}}$$

My entry is different from what I told you to enter because I had to enter it in degrees!

Make sure your calculator is in degrees (or radians ) if that is what you want.

there will most likely be a little R or D at the top of the screen.

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Now do you mean

$$8cos^2(0.6) + 3 \quad ?$$

it is probably

$$8*(cos0.6)\;\;[x^y]\;\;2+3$$

Try that

the answer should be

$${\mathtt{8}}{\mathtt{\,\times\,}}{\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{cos}}{\left({\mathtt{0.6}}^\circ\right)}}^{\,{\mathtt{2}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{3}} = {\mathtt{10.999\: \!122\: \!733\: \!907\: \!187\: \!4}}$$

Actually that is odd - are you sure that is what you want?  Is it in degrees?  0.6 degrees is a tiny angle.

Maybe it is in radians??

If there is confusion - let us know :)

Its in Radian and the Answer on maths text book is 5.8989

Its about derivatives

Question is Calc the rate of change of i(t) = 4 sin 2t + 3t, when t = 0.6.

and answer is 5.8989  how do i compute it on casio fx-82MS ???