Question

plse explain thisssss

Answer 1

what's \(\large cos^{-1}(\theta)\ ?\)

Answer 2

who?

Answer 3

5pi/4

Answer 4

but, \(\large cos^{-1}(\theta)\ ?\) means what exacly in terms of \(\theta\)?

Answer 5

what is it saying?

Answer 6

i didn't understand

Answer 7

ok, what does it mean to say \(\large cos^{}(\pi)=-1\ ?\)

Answer 8

yes

Answer 9

do you know what an arcCosine function is?

Answer 10

yes

Answer 11

so, what is it?

Answer 12

cos^-1(cosx) =x

Answer 13

correct

Answer 14

so \(cos^{-1}(\theta)\) means, "the COSINE VALUE for the angle \(\theta\)

Answer 15

cos theta

Answer 16

actually one sec, I got a bix mixed up

Answer 17

it means the ANGLE for such VALUE, so \(cos^{-1}\) gives you the ANGLE, not the value, cos gives you value

Answer 18

$$
cos^{-1}\pmatrix{cos\pmatrix{\color{blue}{\cfrac{\pi}{4}}}}\\
cos\pmatrix{\color{blue}{\cfrac{\pi}{4}}} = \text{some value}\\
cos^{-1}(\text{some value}) \implies \text{what is the ANGLE whose value is "some value"}\\
cos^{-1}(\text{some value}) = \color{blue}{\cfrac{\pi}{4}}
$$

Answer 19

what THAT value is, doesn't really matter, because we don't need to know it :), since we want the angle

Answer 20

Ya @msingh its correct, why you bumped the question ?