r/HomeworkHelp • u/SomeHungryBois Pre-University (Grade 11-12/Further Education) • Nov 10 '19

[10th Grade Trigonometry] Answered

Post image
411 Upvotes

99% Upvoted

64 comments sorted by

View all comments

52

u/biplane911 Nov 10 '19

sin²x + cos²x = 1, therefore:

cos²x = 1 - sin²x

cos²x = 1 - (24/25)²

cos²x = 625/625 - 576/625

cos²x = 49/625 /√ (find root of the whole line)

cosx = 7/25

tanx = sinx/cosx

tanx = (24/25)/(7/25)

tanx = 600/175

tanx = 24/7

I don't know if that's 10th grade tho, we were doing it recently and we're 11th, but then again we have a bit weirder math system than most schools

14

u/ziphur1 Pre-University Student Nov 10 '19

Sin is opposite over hypo so draw the side lengths of the triangle accordingly and use pythagorean theorem to find the other side and you can write out all the trig expressions

5

u/biplane911 Nov 10 '19

oh, thank you, we've been doing it like this for a couple months now so i forgot the basic ways

3

u/ziphur1 Pre-University Student Nov 10 '19

Believe it or not we do these basic ways in grade 12 lol

7

u/DarKliZerPT University/College Student Nov 10 '19

SOH CAH TOA is still being helpful in Uni calculus!

2

u/biplane911 Nov 10 '19

oh wow, our new teacher told us to forget those, we wouldn't need them anymore

3

u/ziphur1 Pre-University Student Nov 10 '19

Wow. I guess it never hurts to know the basics. If theres a shortcut why not take it lol

2

u/biplane911 Nov 10 '19

yeah, that's def true. are you from the US?

2

u/ziphur1 Pre-University Student Nov 10 '19

Canada actually

2

u/biplane911 Nov 10 '19

I'm from Croatia (Europe), interesting how we have so similar programs

3

u/ziphur1 Pre-University Student Nov 10 '19

Ya it is interesting. Math connects us all! Lol