2
2.6 पाइथागोरस प्रमेय के अनुसार,
(आधार)2 + (लम्ब)2 3
a) (केंद्र)
b) (कोण)2
c) (कर्ण)
According to Pythagoras theorem, (Base)2 + (Perpend
a) (Centre)
b) (Angle)
c) (
7 A(2,4) तथा B(6,8) बिंदओं का मध्य बिंदु है-
The mid point of the points A(2,4) and B(6,8) is -
a) (4,6)
c) (3,5)
b) (6,4)
2.8 त्रिकोणमितीय सर्वसमिका :-
Trigonometric identity: -
sin? A + cos? A =
sin2 A + cos2 A =
Answers
Question 2.6) :- According to Pythagoras theorem, (Base)² + (Perpendicular)² :-
a) (Centre)²
b) (Angle)²
c) (Hypotenuse)²
Solution :-
A right angle ∆ , has three sides as Perpendicular, Base and hypotenuse.
Pythagoras theorem :- The sum of the squares of the lengths of the legs of a right triangle is equal to the square of the length of the hypotenuse .
Or,
→ (Base)² + (Perpendicular)² = (Hypotenuse)²
∴ option (C) (Hypotenuse)² is right Answer.
___________________
Question 2.7) The mid point of the points A(2,4) and B(6,8) is :-
a) (4,6)
c) (3,5)
b) (6,4)
Solution :-
The mid - Point of (x1 , y1) and (x2, y2) is given by :-
→ x = (x1 + x2) / 2
→ y = (y1 + y2) / 2
we have given that,
- x1 = 2
- y1 = 4
- x2 = 6
- y2 = 8
Putting values we get :-
→ x = (2 + 6)/2 = 8/2 = 4 .
→ y = (4 + 8) / 2 = 12/2 = 6.
Therefore,
Mid - Points of the given Points is (4,6) . (Option A)
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Question 2.8) Trigonometric identity : -
sin²A + cos²A = ?
Solution :-
we know that,
- sinθ = (Perpendicular) / (Hypotenuse) = P/H
- cosθ = (Base) / (Hypotenuse) = B/H
So,
→ sin²θ + cos²θ
→ (P/H)² + (B/H)²
→ (P²/H²) + (B²/H²)
→ (P² + B²) / H²
Now, According to Pythagoras theorem, (Base)² + (Perpendicular)² = (Hypotenuse)²
→ (P² + B²) = H²
So,
→ (P² + B²) / H²
→ H² / H²
→ 1 .
Therefore,
→ sin²A + cos²A = 1. (Ans.)