Question

limx→0 1-cos2x/xsinx=2?​

Answer 1

Q. limx→0 1-cos2x/xsinx=2?

→ 1 - infinite

See the attachment

Thanks

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Given,

An A.P. whose nth term is given by, $\sf{a_n~=~A_n~+~b}$

→ We need to find the sum of first 20 terms.

To find the sum of the n terms of the given A.P.,

we use the formula,

$\longrightarrow~\sf{S_n~=~\dfrac{n~(a~+~l)}{2}}$

Where,

• a = the first term

• l = the last term

Putting “n = 1” in the given $\sf{a_n}$ we get,

→ a = A(1) + B = A + B

For the last term (l), here n = 20

→ A₂₀ = A(20) + B = 20A + B

→ S₂₀ = $\sf{\dfrac{20}{2}~\bigg((A~+~B)~+~20A~+~B\bigg)}$

→ S₂₀ = 10 [21A + 2B]

→ S₂₀ = 210 A + 20B

Therefore, the sum of the first 20 terms of the given A.P. is (210 A + 20B)

Answer 2

Step-by-step explanation:

210 +A+B Is the correct

hope it helps