Find dy/dx
y=(116-21x^2)/120

Hi! I dont understand what to do here, please help!

Question

Find dy/dx 
y=(116-21x^2)/120

Hi! I dont understand what to do here, please help!

anonymous · Answer

$$y=\frac{ 116-21x^2 }{ 120 }$$


here is the equation again

seascorpion1 · Answer

$$y=\frac{116}{120}-\frac{21}{120}x^2$$
therefore:
$$y'=-\frac{21*2}{120}x^{2-1}$$$$=-\frac{21}{60}x$$

dayakar · Answer

$$y= \frac{ 116 }{ 120 }-\frac{ 21x^{2} }{ 120 }$$

dayakar · Answer

now find dy/dx

anonymous · Answer

the $$\frac{ 116 }{ 120 } $$ goes to zero when applying the power rule (I think thats what its called) right? and then the next part goes to $$\frac{ -21 }{ 60 }x$$ but  the answer in my text book says its -7x/20, so you divide both sides by three to get that

dayakar · Answer

-21x/60  (cancellation with 3 )
=-7x/20

dayakar · Answer

u r right

anonymous · Answer

Ok great! Thanks! :D

dayakar · Answer

u r welcome:)