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Showing posts with label Model Papers 2021. Show all posts
Showing posts with label Model Papers 2021. Show all posts

Wednesday, 14 July 2021

Mathematics Paper II - For Class XII (Science Group) - Solved Model Paper 2021 -Section "B" And "C" - By Sir Abdul Ahad

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Mathematics Paper II
Solved Model Paper 2021 -Section "B" And "C"


By Sir Abdul Ahad
Special Thanks To Sir Fahad And Sir Adnan Akhter


For Model Paper With Solved MCQs Click Here























Tuesday, 13 July 2021

Mathematics - Paper I - For Class XI (Science Group) - Model papers With Solved Section "B" and "C" - 2020 -2021

Go To Index
Mathematics - Paper I
For Class XI (Science Group)
Solved Model papers 2020 -2021


By Sir Abdul Ahad
Special Thanks To Sir Fahad And Sir Adnan Akhter



For Solved MCQs and Model Paper CLICK HERE





















SECTION 'C'

Q.7.(i) Prove any two of the following:
(a) Cos4x = 8 Cos4 x - 8 Cos2 x + 1

Proof:
Taking L.H.S
L.H.S
= Cos4x
= Cos(2x + 2x)
∴ Cos(α + β) = Cosα Cosβ - Sinα Sinβ
= Cos2x + Cos2x - Sin2x Sin2x
=Cos22x - Sin22x
∴ Cos2x = 2Cos2x - 1
∴ Sin2x = 2Sin x - Cos x
= (2Cos2 x - 1)2 - (2Sin x Cos x)2
= 4Cos4 x - 4Cos2 x + 1 - 4Sin2 x Cos2 x
= 4Cos4 x - 4Cos2 x + 1 - 4Cos2 x (1 - Cos2 x)
= 4Cos4 x - 4Cos2 x + 1 - 4Cos2 x + 4Cos4 x
= 8Cos4 x - 8Cos2 x + 1 
⇒ L.H.S = R.H.S
Hence proved

Q.7 (i) b:

Q.7 (i) c:

(ii) The measure of the two sides of a triangle are 4 and 5 units. Find the third side so that the area of the triangle is 6 square units.

OR

(ii) In the expansion of ( x2 + 1 / x2)m, m∈N, the binomial coefficient of the fourth and the thirteenth term are equal to each other, find the eleventh term.

Friday, 25 June 2021