AIBU to ask for help with a Maths question?

[PianoExam]

DD is struggling with an A-Level Maths question about Trigonometric functions. I have attached a photo of the question.

Does anyone have any ideas?

Let y = arccos(x)
Cos(y) = x
1 - cos2(y) =1- x2
Sin2(y) =1- x2
Sin(y) = sqrt (1-x^2)

Tan(y) = sin(y)/cos(y)
= sqrt(1-x^2)/x

Y = arc tan (sqrt(1-x^2)/x)

Yabvu

I am struggling with year 6 maths and I’m an accountant....

You are so clever. I'd have no idea where to start. Your daughter must be a genius. I am so glad my secondary school kids don't ask me for help.

42

I should add, the difference between the two questions is in the domain given for x. Hope this helps.

Assuming Bracco hasn't just written down a load of random letters/numbers for fun - BRAVO!

@BrumBoo

@Bracco

Let y = arccos(x) Cos(y) = x 1 - cos2(y) =1- x2 Sin2(y) =1- x2 Sin(y) = sqrt (1-x^2)

Tan(y) = sin(y)/cos(y)
= sqrt(1-x^2)/x

Y = arc tan (sqrt(1-x^2)/x)

As any fule kno

@Bracco

Let y = arccos(x) Cos(y) = x 1 - cos2(y) =1- x2 Sin2(y) =1- x2 Sin(y) = sqrt (1-x^2)

Tan(y) = sin(y)/cos(y)
= sqrt(1-x^2)/x

Y = arc tan (sqrt(1-x^2)/x)

Thank you so much. That's brilliant 😊. I will relay this to DD

@WithinAForestDark

@Bracco

I should add, the difference between the two questions is in the domain given for x. Hope this helps.

Thanks so much!