#3rd questtion
159 messages · Page 1 of 1 (latest)
It's from JEE practice?
Ok so we have a triangle formed from the lines, and you first wanna get vertices of it.
12th
K
You do that by calculating the intersections
K
OK
Yes can u do that?
is answer (0,pi)
Yep
I don't have that one but maths sir send us to do that
My badd
I listend about it
Yeah i assume this is correct ima trust u
So now you wanna determine which side of the lines
?
Which side of the lines is “inside” the triangle
brilliant ques in that book tbh...
How do i explain this
- Find the vertices of the triangle ( intersection )
- Set inequalities for a point inside the triangle:
Consider first, second and third eqn as L1, L2, and L3 respectively.
Okay?
I am getting stuck in inequalities
Yeah
I meant setting inequalities lol
what ru struggling with?
Like if it lies inside it is greater than
Yeah exactly
If it is touching it is equal
If it is out side less than
How can I write that expression
Let me explain. See the line: let's say the x-2y+2 = 0, it divides the plane into points where x-2y+2 > 0 ( side 1 ) and x-2y+2 < 0 ( side 2 ).
To be inside the triangle, a point must be on the correct side of each line.... and the correct side depends on which side of the line the triangle is on.
Yeap
For the line: x-2y+2 = 0, we can test a point known to be inside the triangle to determine the direction:
- Example: Take the intersection of the other two lines as a test point.
- Substitute that point inro x - 2y + 2; if it's positive, then " inside ", means x-2y+2 > = 0.
Similarly, for the other lines, substituting a point inside the triangle tells you wheter the inequality is <= 0 or >= 0
So, the choice of ≥ 0 or ≤ 0 is just to make sure the point is on the side of the line where the triangle actually lies.
K
Now, let P(a,sina) lie inside the triangle, then it must satisfy all there inequalities corresponding to the triangle sides.
K
L1: x−2y+2 ≥ 0 ⟹ a−2sina+2 ≥ 0 ⟹ 2sina ≤ a + 2
Hey angles can be negative
L2: x+y ≤ 0 ⟹ a+sina ≤ 0
L3: x−y−π ≤ 0 ⟹ a−sina−π ≤ 0 ⟹ sina ≥ a−π
Yes, ‘a’ can be slightly negative, because the inequalities allow it.
@dreamy elbow I understand
K
Next step
Nice
After finding inequality
Did u yet?
sina ∈ [−1,1], so approximate constraints:
- 2sina ≤ a+2 ⟹ 2(−1) ≤ a+2 ⟹ −2≤a+2⟹a≥−4 (always true for real a > 0 )
- a + sin a < = 0 ==> a≤−sina≤1
- sina≥a−π⟹ 1≥a−π⟹ a≤π+1
Bruh
The tightest restriction:
a∈(0,π) for the point to be inside
Hey let him do it
I always try to remember que type
You’re not supposed to just send them answers
I don't get idea by my self
Oh okay!
Alr hold oan
Then?
I tried my best to think like a JEE student, now I'm in my 2nd year in Bachelors!
@dreamy elbow Did you attempt JEE?
Even my physics too. I got -1 in Physics mains exams, and -2 in chemistry mains, Math was 100/100 both the times 😂
Lol
as per NTA key, I calculated my marks
Adv
after writing second shift I qualified to Advanced
once again, math was full, in both papers, but phy chem very very less
I can easily get 40 to 60 marks in chem weekly exam
Math 60-70
Phy 5-10
Out of 100
Quite similar in phy
Solve em
I literally solved everything and gave him the soln
It would be cheating
Cause I already seen the soln of pvssp_gg
K I stucked
I can't match the last 2 eqn
Did you get this somewhere
Nope
I didn't got that
bro, let's try this, search for MATH GPT in google, it'll generate videos also
Thank you for giving me this tool
Can u give me some math boost up tips
And what should I do in exam first
Be careful with the domain of the functions
What
Not only chapter but full math sub tips
?
I understand
congrats
Thanks
you're welcome
so the answer is (0, pi) option C
right?
I wonder if there's a way to solve algebraically
What
is my answer correct?
Yep
nice