https://www.quora.com/profile/Bravewarrior/p-143521002

Here is the question and solution. I need help with part b. I don't understand why at the end they have negative root 3 over 4. I thought that as cos squared theta = 3/4 so by square rooting both sides therefore cos theta =plus minus root 3 over 2. Some help would be great!

Here is the question and solution. I need help with part b. I don't understand why at the end they have negative root 3 over 4. I thought that as cos squared theta = 3/4 so by square rooting both sides therefore cos theta =plus minus root 3 over 2. Some help would be great!

Original post by pigeonwarrior

https://www.quora.com/profile/Bravewarrior/p-143521002

Here is the question and solution. I need help with part b. I don't understand why at the end they have negative root 3 over 4. I thought that as cos squared theta = 3/4 so by square rooting both sides therefore cos theta =plus minus root 3 over 2. Some help would be great!

Here is the question and solution. I need help with part b. I don't understand why at the end they have negative root 3 over 4. I thought that as cos squared theta = 3/4 so by square rooting both sides therefore cos theta =plus minus root 3 over 2. Some help would be great!

Agree with you. It's a well known trig value.

Original post by mqb2766

Agree with you. It's a well known trig value.

I guess the solution is wrong...😭

Original post by pigeonwarrior

I guess the solution is wrong...😭

Yup. It's a 1:sqrt(3):2 right triangle and you can read the trig values off that.

Original post by mqb2766

Yup. It's a 1:sqrt(3):2 right triangle and you can read the trig values off that.

Thank you!!! 🙂

- maths a level
- national 5 maths help
- Further maths and maths A level help
- A level physics without maths
- how to improve on alevel biology math questions
- Can i go from 4 to 7 in 6 weeks (Edexcel)
- Isaac Physics SPC Summer School
- Is the physics in an Engineering degree much harder than A Level physics?
- A Level Maths Checklist
- GCSE Mathematics Study Group 2023-2024
- How should i be revising for maths?
- How to quickly improve in maths
- Pharmacy interview in wolverhampton
- A level Maths HELP
- A*A* in maths + further maths A level - ask me anything
- YR12 Mocks
- How to get improve general problem solving skills and for MAT
- Maths gcse
- GCSE Maths Tips and Tricks!
- Revision

Last reply 2 weeks ago

STEP 2 in 2024: Sharing Your Story! [PLUS WITH SOME SOLUTIONS AND PREDICTION]Maths

18

80

Last reply 2 weeks ago

A level maths paper 2 (pure and statistics) and paper 3 (pure and mechanics) ocrMaths

4

6

Last reply 2 weeks ago

STEP 2 in 2024: Sharing Your Story! [PLUS WITH SOME SOLUTIONS AND PREDICTION]Maths

18

80

Last reply 2 weeks ago

A level maths paper 2 (pure and statistics) and paper 3 (pure and mechanics) ocrMaths

4

6