Students and Teacher's Forum

Students and Teachers Forum

1. Do you involve yourself in bad activities?

हामी धेरै जना मिलेर विद्यालयमा खेल्छौँ .....

3. Prove that: sin²(120−α)+sin²α+sin²(120+α).

4. Find the separate eqn. of x²- 2xy sin A - y² cos 2A=0.

Here, x2 - 2xy sinA - y2 cos2A = 0 or, x2 - 2xy sinA - y2(cos2A - sin2A) = 0 or, x2 - 2x.ysinA + (ysinA)2 - (ycosA)2 = 0 or, (x - y sinA)2 - (y cosA)2 = 0 or, (x - ysinA + ycosA) ( x - yinA - ycosA) = .....

5. Prove that: Sin3A/sinA - cos3A/cosA =2.

LHS =sin3A / sinA - Cos3A / cosA = [ sin3A cosA - cos3A sinA]/(sinA cosA) = sin(3A - A)/(sinA cosA) = sin2A/(sinA cosA) = 2 sinA cosA/(sinA cosA) = 2 = .....

6. Prove that:
Cot(A + 45) - tan(A - 45)=2cos2A/(1+sin2A).

Here, taking LHS, = cot(A + 45o) - tan(A - 45o) = cos(A + 45o) / sin(A + 45o) - sin(A - 45o)/cos(A - 45o) [ Since, cot= cos/sin & tan= sin/cos.] = [cos(A + 45o)cos(A .....

7. Prove that:
cos17° + sin17°cos17° - sin17° = cot28°.

RHS = cot28° = cos28°sin28° = cos(45° - 17°)sin(45° - 17°) [45° - 17° = 28°] .....

8. Prove that: 1+cos2θsin2θ . 1+cosθcosθ =cotθ 2

Here, LHS = {(1 + cos2θ)/sin2θ}. (1 + cosθ)/cosθ = {(1 + cos2θ) (1 + cosθ)}/(sin2θcosθ) We know, 1 + cos2θ = .....

9. Show the difference between equatorial and tropical climate in four points.

The difference between equatorial and tropical climate is shown in the table below: Equatorial Climate Tropical Climate This .....

10. Prove that: 2tan20+tan35=tan55

We know, 20o = 55o - 35o Take tan of both sides tan20o = tan(55o - 35o) or, tan 20o = (tan 55o - tan 35o)/(1+ tan 55o tan 35o) but ,as 55o + 35o = 90o so tan 35o = .....

11.
Prove that: Cos⁶A - sin⁶A=1/16(15cos2A + cos6A).

Taking LHS = (cos6A - sin6A) = [(cos2A)3 - (sin2A)3] Using formula of a3 .....

12. If 4 sinA = 3, find the value of cos2A.

Here, 4 sinA = 3 or, sinA = 3/4 Now, Cos2A = 1 - 2 sin2A = 1 - 2(3/4)2 = 1 - 9/8 = .....

13. Express CosA/4 in terms of sinA/8.

We know, cosA/4 = cos2(A/8) = 1 - 2 .....

14. Express tan2A in terms of tanA.

Here, Tan2A = 2tanA / (1 - tan2A) is the required .....

15. Express sinA in terms of sinA/2 & cosA/2.

SinA = 2 sinA/2.cosA/2 is the required .....

16. What is neutralization?

A reaction between an acid and a base to form salt and water is called .....

17. What are good habits?

Good habits are the list of behaviours which bring positive change to the individual and society. They are behaviours that maintain peace and harmony in the .....

18. What is thrust?

The total force acting on a given surface is called .....

19. Rewrite the following sentences using used to.

1. I didn’t like eating spinach.
2. She's friendly now but we didn’t like each other.
3. Didn't you live in our road?
4. Didn't you have a cat?
5. She didn't behave so badly.

1. I used not to like eating spinach. 2. She's friendly now but we used not to like each other. 3. Didn't you use to live in our road? 4. Didn't you use to have a cat? 5. She didn't use to behave so .....

20. दिइएको चित्रभित्र रहेको खाली ठाउँमा 'व' सँग जोडेका आधा अक्षरहरूबाट बनेका पाँच वटा शब्दहरू लेख्नुहोस् ।

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21. If x = 4, y = 5 and z = 6, find the value of:

7x + 5y - 4z - 3y

7x + 5y - 4z - 3y = 7 × 4 + 5 × 5 - 4 × 6 - 3 × 5 = 28 + 25 - 24 - 15 .....

22. Name any three works of people:

1. ______

2. ______

3. ______

1. Pilot 2. Shopkeeper 3. Gardener .....

23. Who are street children? How do they become street children?

The children who have quitted their home or have no home and who live in the streets of big cities are called street children. They become street children because their parents are dead or have abandoned them. Their .....

24. तलको शब्द उस्तै सार्नुहोस् :

टहटह

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25. Write the name of any two natural sources of air pollution.

A volcanic eruption and forest fire are the sources of air .....

26. It is the biggest bird. It can run on flat lands as fast as a horse. It is found mainly in Africa. Name it.

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27. Tick the right one from the brackets.

(Penguin/ Giraffe) is found in grassland.

(Penguin/ Giraffe✓) is found in .....

28. तलको शब्द उस्तै सार्नुहोस् :

जलथल

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29. दिइएको चित्रभित्र रहेको खाली ठाउँमा 'व' सँग जोडेका आधा अक्षरहरूबाट बनेका पाँच वटा शब्दहरू लेख्नुहोस् ।

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30. तलको शब्द उस्तै सार्नुहोस् :

मलम

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31. तलको शब्द उस्तै सार्नुहोस् :

मटर

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32. What is the food of Seri and Eri silkworm?

The food of Seri silkworm is Mulberry leaves and Eri silkworm is castor .....

33. List out any three alcoholic drinks.

The examples of three alcoholic drinks are: i) Vodka ii) Beer iii) .....

34. तल दिइएका अक्षरहरू मिलाएर शब्दहरू बनाउनुहोस् :

१. झलमल २. छलफल ३. कलकल ४. दमकल ५. .....

35. तल दिइएका अक्षरहरू मिलाएर शब्दहरू बनाउनुहोस् :

१. नहर २. नक्षत्र ३. नरम ४. नजर ५. .....

36. तल दिइएका अक्षरहरू मिलाएर शब्दहरू बनाउनुहोस् :

१. तल २. तप ३. तह ४. तर ५. .....

37. वाक्य बनाऊ :

तपाईं

तपाईं खाना खानुहोस् .....

38. तल दिइएका अक्षरहरू मिलाएर शब्दहरू बनाउनुहोस् :

१. जल २. जप ३. जग ४. जस ५. .....

39. Prove that:
cos² A+ sin² A.cos 2B = cos² B+ sin² B. cos 2A

Here, LHS = cos2 A+ sin2 A.cos 2B = cos2 A+ sin2 A(1 - 2 sin2 B) = cos2 A+ sin2 A - 2 sin2 A sin2 B) = 1- 2 sin2 A. sin2 .....

40. तलको शब्द उस्तै सार्नुहोस् :

वरपर

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41. Find the slope of the line perpendicular to the straight line 3x-4y=10.

Here, Given equation of line is 3x-4y=10................... (i) Slope of equation (i) is; m1= - coeff. of x coeff. of y = 3-4 = 34 Slope of perpendicular line to line to line (i) (m2) = --134 = - 43 .....

42. तलको शब्द उस्तै सार्नुहोस् :

मलमल

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43. चित्र हेरी जोडा मिलाऊ :