trigo

[river otter]

Hi can anyone help I don’t understand what the 1st qns means much thanks!

[misty dagger]

1. Ask your question and show the work you've done so far. If you've posted a screenshot of a question, specify which part you need help with.
2. Wait patiently for a helper to come along.
3. Once someone helps you, say thank you and close the thread with:

   +close
   

4. Feel free to nominate the person for helper of the week in #helper-nominations
5. Do not ping the mods, unless someone is breaking the rules.
6. If you're happy with the help you got here, and the server overall, you can contribute financially as well:

[blazing grove]

Given those facts about angles A and B, find the desired trig values.

,rotate

[river otter]

sin a= 53.130 and b is 18.834?

[blazing grove]

clearly not

sin(A) = -4/5

[river otter]

my bad -53.130

[blazing grove]

that also used a calculator, so not relevant

Like from CAST rule both A and B have to be in the 3rd quadrant

use trig identities

[river otter]

i see but why are there 4 values

[blazing grove]

... cause you're asked... part i-iv

that's 4 questions

so 4 values to find

[river otter]

wait are they 2 different triangles..?

[blazing grove]

tf you on about

there are no triangles

Like write sin(2A) in terms of the basic ratios of just A

[river otter]

so sin 2a is 2*(-4/5)?

[blazing grove]

idk, is sin(2A)=2sin(A)?

[river otter]

they arent right

[blazing grove]

they are not.

write sin(2A) in terms of trig ratios of A.

hint: you're just quoting an identity, literally no thinking should happen lol

[river otter]

sin over cos

[blazing grove]

????????????????????

what is the double angle formula for sin?

[river otter]

im really sorry im really slow

[blazing grove]

go check your notes

or google

if you dont know.

[river otter]

2tan over(1-tan^2)

[blazing grove]

$\sin(2A)=2\sin(A)\cos(A)$

[true widget]

Omegabet_

[blazing grove]

read your notes next time.

but anyway, so clearly you need to find the values of sin(A) and cos(A)

one of them should be trivial to find

[river otter]

ohh i mixed them up sorry

[blazing grove]

you evidently did.

but anyway, you now find cos(A) since it's clear what sin(A) is

[river otter]

cos a is 3/5

[blazing grove]

no

cos is negative in the 3rd quadrant

[river otter]

oh so -3/5

[blazing grove]

,calc sqrt(1-(4/5)^2)

[true widget]

Result:

0.6

[blazing grove]

yes

[river otter]

so sin a should=24/25

[blazing grove]

no......

sin(A)=-4/5...

you want sin(2A)

[river otter]

i thought there was a 2 infront of sin

[blazing grove]

you just wrote sin(A)=24/25

which is wrong. You likely meant to write sin(2A)=24/25

[river otter]

oh yeah

so sin2a=24/25

[blazing grove]

yes

now repeat similar processes for the rest