Original post by staerryynighht
can someone solve this prove that
cosx+sinx+sinx/cosx =secx
cosx+sinx+sinx/cosx =secx
Is it solve or prove?
are there brackets on the left?
Can you upload the original question pls
Original post by staerryynighht
can someone solve this prove that
cosx+sinx+sinx/cosx =secx
cosx+sinx+sinx/cosx =secx
That doesn't look plausible tbh. Can you upload a picture of the original question?
Original post by davros
That doesn't look plausible tbh. Can you upload a picture of the original question?
hey can you pls help solving part c
Original post by staerryynighht
hey can you pls help solving part c
What did you sketch for a)
Can you picture what lines with gradient 1/2 and intercept k would not intersect?If
But to solve it, remove the absolute value function as usual and solve for k. When is an intersection point impossible?
Multiply cos x on both sides:
cos^2 x + cos x sin x + sin x = 1
1 - sin^2 x + cos x sin x + sin x = 1
- sin^2 x + cos x sin x + sin x = 0
sin x (-sin x + cos x +1) = 0
So sin x = 0 or -sin x + cos x +1 = 0
I've reduced the question to something you should be able to solve
cos^2 x + cos x sin x + sin x = 1
1 - sin^2 x + cos x sin x + sin x = 1
- sin^2 x + cos x sin x + sin x = 0
sin x (-sin x + cos x +1) = 0
So sin x = 0 or -sin x + cos x +1 = 0
I've reduced the question to something you should be able to solve
cosx+sinx+sinx/cosx =secx (multiply by cosx on both sides)
cos^2 x+cosx sinx+sinx = 1
1-sin^2 x+cosx sinx+sinx = 1
-sin^2 x+cosx sinx+sinx = 0
sin x (-sin x+cosx+1) = 0
Hence sinx=0 or -sin x+cosx+1=0
Reduced to something you can solve.
cos^2 x+cosx sinx+sinx = 1
1-sin^2 x+cosx sinx+sinx = 1
-sin^2 x+cosx sinx+sinx = 0
sin x (-sin x+cosx+1) = 0
Hence sinx=0 or -sin x+cosx+1=0
Reduced to something you can solve.
Original post by PhysiKKid
cosx+sinx+sinx/cosx =secx (multiply by cosx on both sides)
cos^2 x+cosx sinx+sinx = 1
1-sin^2 x+cosx sinx+sinx = 1
-sin^2 x+cosx sinx+sinx = 0
sin x (-sin x+cosx+1) = 0
Hence sinx=0 or -sin x+cosx+1=0
Reduced to something you can solve.
cos^2 x+cosx sinx+sinx = 1
1-sin^2 x+cosx sinx+sinx = 1
-sin^2 x+cosx sinx+sinx = 0
sin x (-sin x+cosx+1) = 0
Hence sinx=0 or -sin x+cosx+1=0
Reduced to something you can solve.
According the OP it's a "prove that" question which implies an identity, but their original post wasn't particularly clear
Original post by davros
According the OP it's a "prove that" question which implies an identity, but their original post wasn't particularly clear
It shouldn't be an identity - substitute x=pi/3 and you'll see that both sides aren't equal.
Original post by PhysiKKid
It shouldn't be an identity - substitute x=pi/3 and you'll see that both sides aren't equal.
That's why we were querying it! It doesn't look right but the OP hasn't come back to clarify or supply the original question
Quick Reply
Related discussions
- Computer science alevel
- Science subjects + a humanity for A Level?
- 16-18 Education
- Bad predicted grades in year 12
- CHange alevel choices
- Medicine HELP
- A-level decision help - Medicine at oxbridge
- Economics degree/apprenticeship
- Question about lse accounting and finance
- Can I study economics/computer science at uni without maths a level?
- FM as an A-Level
- Maths for economics at Nottingham university
- A level options
- Can i go into quant finance if im not going to a "top 5" university?
- How much Maths in Biology and Psychology A Level?
- Biology and chemistry
- A level physics without maths
- A level choices
- Should I take core maths?
- Does anyone actually care about A-Level Computer Science?
Latest
Trending
Last reply 2 days ago
Did Cambridge maths students find maths and further maths a level very easy?Last reply 2 weeks ago
Edexcel A Level Mathematics Paper 2 unofficial mark scheme correct me if wrongMaths
71
Trending
Last reply 2 days ago
Did Cambridge maths students find maths and further maths a level very easy?Last reply 2 weeks ago
Edexcel A Level Mathematics Paper 2 unofficial mark scheme correct me if wrongMaths
71
