Question

for what value of x will the derivative of y = (sin2x)/4 + x/2 = 1?

a. pi/3

b.O

c.pi/2

d.pi/4

Answer 1

i get answer 0 but can u check guys if its true

Answer 2

is this
\[y=\frac{\sin(2x)}{4}+\frac{x}{2}\]?

Answer 3

yes yes

Answer 4

\[y'=\frac{\cos(2x)}{2}+\frac{1}{2}\]

Answer 5

x=0

Answer 6

cos(2x)=-1
2x=0
x=0

Answer 7

then you want
\[y'=\frac{\cos(2x)}{2}+\frac{1}{2}=0\]
\[\cos(2x)=-1\]
\[2x=\pi\]
\[x=\frac{\pi}{2}\] is one answer

Answer 8

its C

Answer 9

yes, it is C

Answer 10

i feel not the answer is zero because a c and d have a pi then my prof is very tricky about question thx satelite

Answer 11

@sam, cos(0)=1, not -1

Answer 12

Im saying
cos(2x)=-1
\[2x=\cos ^{-1}(-1)\]
\[2x=\pi\]
\[x=\pi/2\]

Answer 13

@satellite73

Answer 14

yes exactly

Answer 15

y' = 1/2 (1 + cos(2x)) = 1;

cos(2x) = 1;

2x = 0;

x = 0°

Answer 16

again !?

Answer 17

the answer is 0 I'm sure but be careful, don't write 0 degrees, it's 0 radians...so just write 0

Answer 18

just to be sure here the question is when will the derivative of the function y be equal to 1?