Hints :
I saw this in a list of previous examination questions today and became intrigued. It asks:
"The acute angle x radians is such that tan(x) = k. Express, in terms of k, sin(x)."
The obvious answer is k cos(x). But as a 2 mark question I get the feeling that something else is required (and I'm not sure if cos(x) counts as 'in terms of x').
I have feeling there's something deceptively obvious here than I'm missing. Can anyone give me hints, or am I overthinking this?
Are well known the identities...
(1)
(2)
If You can use and as function of instead of very well!... otherwise You can devide (1) and (2) and obtain...
(3)
... the use (3) to find as function of and then substitute in (1) and (2)... a very tedius job!...
Kind regards