Question

2cos x^2 -4x^2 sin x^2=0

could someone please help me with this

Answer 1

first you would want to make x^2 a variable say= y

Answer 2

then you have a simpler equation

Answer 3

i tried that too, im still stuck :(

Answer 4

@ganeshie8

Answer 5

@AriPotta @Abhisar @BOOKER23 @DivineSolar @fatima0520 @hari5719 @shifuyanli

Answer 6

   2cos²x + sinx - 2 = 0
2(1-sin²x) + sinx - 2 = 0
 2 - 2sin²x + sinx - 2 = 0
         -2sin²x + sinx = 0
           2sin²x - sinx = 0
        sinx(2sinx - 1) = 0

         solutions are for:
i. sinx = 0 ⇒ x = 0, π, 2π  ✔
ii. 2sinx - 1 = 0
        2sinx = 1
          sinx = 1/2
              x = π/6  , 5π/6  ✔

       ANSWER
x = 0, π/6, 5π/6, π, 2π

Answer 7

@bohotness I cant understand how you got:

 2cos²x + sinx - 2 = 0

Answer 8

@bohotness the question is actually:

2cos (x^2) -4x^2 sin (x^2)=0

Answer 9

Okay

Answer 10

What are we supposed to do? solve for x?

Answer 11

yes

Answer 12

actually is this part of a longer problem but im stuck on that, i mean to look for the point of inflection of a graph and this is the second derivatice

Answer 13

oh man, please, post the original one.

Answer 14

Sketch the graph of the function y=sin(x2) for −2π≤x≤2π

Answer 15

https://www.desmos.com/calculator/ln4cyvqy2e

Answer 16

yes i know, but i have to show the work to get to the answer. thats why i posted this

Answer 17

im stuck while trying to solve2cos (x^2) -4x^2 sin (x^2)=0

Answer 18

To me, just assign the value of x and calculate y. Only thing to do is finding out where y =0

Answer 19

when you make it x , then equate it to both sides

Answer 20

The amplitude of the function is 1, hence the min/ max are just -1,1
sin (x^2)=0 iff x ^2 =0 or x^2 =pi , solve for them.

Answer 21

then you can divide from there you may get tan

Answer 22

I think you make it more complex when you take first and second derivative to find max/min/ inflection one or concave up/down. No need to do that since trig functions have only one shape :) (the wave one)

Answer 23

no iits not derivative if you do it that way you will get 2cosx=4xsinx

Answer 24

then tan^-1((1/2(x))

Answer 25

is equal to x

Answer 26

sorry i think human calculator has done it all

Answer 27

@Loser66 I am trying to find the exact coordinates of the point of inflection

Answer 28

How? look at this http://www.wolframalpha.com/input/?i=%28sin%28x^2%29%29%22%3D0