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Ask QuestionPosted by Aditi Shenoy 3 years, 11 months ago
- 2 answers
Yogita Ingle 3 years, 11 months ago
Given: A ∆ XYZ in which ∠XYZ = 90°.
To prove: XZ2 = XY2 + YZ2
Construction: Draw YO ⊥ XZ
Proof: In ∆XOY and ∆XYZ, we have,
∠X = ∠X → common
∠XOY = ∠XYZ → each equal to 90°
Therefore, ∆ XOY ~ ∆ XYZ → by AA-similarity
⇒ XO/XY = XY/XZ
⇒ XO × XZ = XY2 ----------------- (i)
In ∆YOZ and ∆XYZ, we have,
∠Z = ∠Z → common
∠YOZ = ∠XYZ → each equal to 90°
Therefore, ∆ YOZ ~ ∆ XYZ → by AA-similarity
⇒ OZ/YZ = YZ/XZ
⇒ OZ × XZ = YZ2 ----------------- (ii)
From (i) and (ii) we get,
XO × XZ + OZ × XZ = (XY2 + YZ2)
⇒ (XO + OZ) × XZ = (XY2 + YZ2)
⇒ XZ × XZ = (XY2 + YZ2)
⇒ XZ 2 = (XY2 + YZ2)
Posted by Jasmeet Kaur 3 years, 11 months ago
- 1 answers
Gaurav Seth 3 years, 11 months ago
1. Practice concentration: Maths and Physics terms and formulas require intense focus and deep concentration to get absorbed into the mind. So you need to work on your concentration level to get all complicated or lengthy formulas stick to your mind.
2. Relax your brain: Maths and Physics problems can never be learned under stress as a stressed brain loses its work potential and finds it difficult to work on complex things. So you need to first relax your mind. By doing this, you will be able to focus more on your task.
3. Practice as much as you can: This may sound like an obvious point, but the more you practice using the formulas you need to know, the more likely you are to remember the same. List down all important formulas on a sheet and whenever you are free, glance at them once. After all, repetition leads to memorization.
4. Minimize your reference checks: Many students think that once they take a glance at a formula, it is in their mind, but the next morning when they try to recall the same, they are shocked to realize that the formula leaked out during the night. To avoid such situation, try to practice solving a problem with the formula without looking it up.
5. Understand the basic concept of the formula: Try to clear your basic concepts before moving ahead with the formulas. This will help you understand the sense of the formula.
For example: In the formula, a = F / m, where acceleration (a) is expressed in terms of Force (F) and mass (m), F is on the top of the fraction. This makes sense, since if you exert more force on an object, it will speed up more quickly. Whereas, mass is on the bottom of the fraction, which means the speed of the object will decrease, since more mass means more inertia thus making the object more difficult to accelerate.
6. Keep away with all distractions: Not only the gadgets you use need to be talked under this heading, but your physical desires like hunger, thirst, drowsiness, etc., also need to be kept away.
7. Learn the derivation of every formula. Derivation of a formula will help you familiarise with the roots and concepts of that formula which can help you retain the same for long time in your brain. Moreover, when you derive a formula, you come across a number of other formulas. That way you can memorize just the bare minimum number of formulae that you need to derive the rest from.
8. Use memorising tricks: Try to create a story that involves everything you are trying to learn. The sequence of a story can help you to remember things in a particular order.
For example: To learn the trigonometric ratios; P/H = sin, B/H = cos, P/B = tan, you can use a phrase “pandit badri prasad har har bole sona chandi tole” and then set the words like:
Work out on more of such phrases that can help you recall the long-complicated formulas.
Thus all the tips and tricks given above if followed wisely, will definitely help you master Maths and Physics, getting you an awesome score in your board exams.
Posted by Vaibhav Panday 3 years, 11 months ago
- 2 answers
Yogita Ingle 3 years, 11 months ago
Find the value of the polynomial 5x – 4x2 + 3 at
(i) x = 0 (ii) x = –1 (iii) x = 2
Solution: (i)x = 0
5x – 4x2 + 3
Plug x = 0 we get
=>5(0) – 4(0)2 + 3
=>0 -0 + 3
=> 3
(ii) x = –1
Plug x = - 1 we get
=>5x – 4x2 + 3
=>5(-1) – 4(-1)2 + 3
=> -5 – 4 +3
=>-6
(iii) x = 2
Plug x = 2 we get
=>5(2) – 4(2)2 + 3
=>10 – 16 + 3
=> -3
Posted by Rani ? 3 years, 11 months ago
- 0 answers
Posted by Tanishka Kushwaha 3 years, 11 months ago
- 1 answers
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- 2 answers
Posted by Yuvraj Bhikane 3 years, 11 months ago
- 1 answers
Posted by Utkarsh Tiwari 3 years, 11 months ago
- 1 answers
Posted by Manu Bhat 3 years, 11 months ago
- 1 answers
Posted by Vivek Mahato 3 years, 11 months ago
- 1 answers
Yogita Ingle 3 years, 11 months ago
(a+b+c)2 = a2+b2+c2+2ab+2bc+2ca
⇒(2x−y+z)2=(2x)2+(−y)2+(z)2+2(2x×−y)+2(−y×z)+2(z×2x)
=4x2 + y2+z2−4xy−2yz+4xz
Posted by Chitralekha Khaund 3 years, 11 months ago
- 2 answers
Chaitanya Saini 3 years, 11 months ago
Pratibha Kushwah 3 years, 11 months ago
Posted by Chitralekha Khaund 3 years, 11 months ago
- 1 answers
Yogita Ingle 3 years, 11 months ago
Total surface area of a cube = 726 cm2
6 × (side)2 = 726
(side)2 = 121
side = 11 cm
Hence, the length of the edge of cube is 11 cm.
Posted by Chitralekha Khaund 3 years, 11 months ago
- 2 answers
Chaitanya Saini 3 years, 11 months ago
Yogita Ingle 3 years, 11 months ago
Let the length be 4x
Let the breadth be 2x
Let the height be x
Surface area=2(lb+bh+hl)
=2(8x²+2x²+4x²)
=28x²=1372
so x²=49
and x=7
So length=4x=28cm
breadth=2x=14cm
&. height=x=7cm
Posted by Arya Dixit 3 years, 11 months ago
- 0 answers
Posted by Rishi Singh 3 years, 11 months ago
- 1 answers
Divya Khola 3 years, 10 months ago
Posted by Hani Soni 3 years, 11 months ago
- 2 answers
Posted by Ritika Date 3 years, 11 months ago
- 1 answers
Posted by Darshan Patel 3 years, 11 months ago
- 0 answers
Posted by Risha Mavi 3 years, 11 months ago
- 1 answers
Gaurav Seth 3 years, 11 months ago
Prove that if the diagonals of a quadrilateral bisect each other, then it is a parallelogram.
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OA = OC and OB = OD [Given]
AOB = DOC [vertically opp. angles]
[SAS congruence]
Therefore 
ABO = CDO (cpct)
From this, we get AB||CD ...(i)
Similarly BC||AD ...(ii)
From (i) and (ii) ABCD is a ||gm.
Posted by Aditya Kumar Saha 3 years, 11 months ago
- 1 answers
Posted by Aiswarya Raanee .K 3 years, 11 months ago
- 2 answers
Posted by Priram Senthil 3 years, 11 months ago
- 0 answers
Posted by Aiswarya Raanee .K 3 years, 11 months ago
- 1 answers
Posted by Aiswarya Raanee .K 3 years, 11 months ago
- 0 answers
Posted by Gurkaran Deep Singh Gill 3 years, 11 months ago
- 1 answers
Posted by Arti Rajput 3 years, 11 months ago
- 2 answers
Arpit Bareth 3 years, 11 months ago
Yogita Ingle 3 years, 11 months ago
Given:
⇒l=30,b=25,h=25
(i) Total S.A of green house
=2(lb+bh+lb)
=2(30×25+30×25+25×25)
=4250 cm2
(ii) For 12 edges: Total length
=4l+4b+4h
=4(30+25+25)
=320 cm
Posted by Darshit Chandra 3 years, 11 months ago
- 5 answers
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Chaitanya Saini 3 years, 11 months ago
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