Differentiation

[rare jolt]

Can someone please help me with b ?

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[jade wharf]

I think you need to recheck the fourth line of (b)

Also how is it true that sin^2(2x)+5sin^2(2x)=6sin^2(4x)?

[shell socket]

why not integrate?

5 sec 2x dx

oh wait mb

values of dy/dx not f(x)

[jade wharf]

Why integratio for solving a trig eqn🫠

[shell socket]

yea find f(x), then find f inverse

[shell socket]

they talking abt x not dy/dx

or am interpretting the question wrong?

[jade wharf]

Bruh the function y is given, look closely

[shell socket]

oh

damn

[shell socket]

sorry bro mb

[jade wharf]

You just differentiate y, equate it to 5/sin2x and solve the trig eq

[rare jolt]

I did not learn integration yet

This is a revised version of whatever I did

[rare jolt]

Can you help me solve the rest ?

[shell socket]

yea i was beign dumb

[shell socket]

always avoid converting from sin x to sin 2x, it increases the number of solution

like when you square x=1
you get x^2 = 1, and x=-1 also becomes a solution, so a similar thing happens here

[stoic slate]

thats just dumb, for x^2 = 1 you have |x|=1 (x= 1, -1)
moreover, there is no conversion in angles anywhere

the argument remains 2x everywhere

[shell socket]

in this solution he has

[shell socket]

what do you need after this?

[jade wharf]

Still wrong, because when you divided both sides by 2, you only divided 5 on the RHS, you should've divided the entire RHS which means both 5 and 5sin^2(2x)

You should get an expression like sin^2(2x)=5/7

[jade wharf]

Can't you see the error she made?

[shell socket]

i didnt try to fix her error i tried to solve thr prroblem

i didnt think one would mess up arithmetic tbh

mb

this is the right ans anyway

[rare jolt]

I feel like I solved it

Ty

[jade wharf]

What is your ans?

[jade wharf]

As a last step, check that if your solutions satisfy the initial eq

[rare jolt]

Alr ty

[jade wharf]

Hey, there are two answers, make sure you find both

[rare jolt]

Here I believe this is fine 😭

[jade wharf]

How did you find 0.564

[rare jolt]

Here

This should be fine 😭

[jade wharf]

Check if they are

[rare jolt]

I don’t have the ms

[shell socket]

use a calculator to check

[rare jolt]

I did

[shell socket]

or maybe desmos for analysis

[shell socket]

do they satisfy the equations?

[shell socket]

and are their values between the interval given (0 to pi/2)

so from 0 to 1.57

[rare jolt]

Shouldn’t the new range be considered

[shell socket]

that range is for 2x

the range of x is retained

like

if i am going double of your speed

and my max speed will be double of yours

so if youre max is v, mine is 2v.. but your max speed still remains v not 2v

get it?

[rare jolt]

Yes 😭😭