2tan30/(1+tan^2 30)=_____
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Answered by
116
2 tan 30/(1+tan^2 30)
2(1√3)/(sec^2 30)
2/√3/(2/√3^2)
2/√3/(4/3)
√3/2= cos 30
2(1√3)/(sec^2 30)
2/√3/(2/√3^2)
2/√3/(4/3)
√3/2= cos 30
Answered by
140
tan 30 = 1/√3
then 2tan30/(1+tan^2 30) is= 2×1/√3 / (1+(1/√3)²)
= 2/√3 / (1+1/3) in brackets by taking 3 as lcm we get
= 2/√3 / (3+1/3)
= 2/√3 / 4/3
= 2/√3×3/4
= 3 / 2√3 (3 can be written as √3×√3)
= √3×√3 / 2√3
= √3/2
= cos 30
then 2tan30/(1+tan^2 30) is= 2×1/√3 / (1+(1/√3)²)
= 2/√3 / (1+1/3) in brackets by taking 3 as lcm we get
= 2/√3 / (3+1/3)
= 2/√3 / 4/3
= 2/√3×3/4
= 3 / 2√3 (3 can be written as √3×√3)
= √3×√3 / 2√3
= √3/2
= cos 30
prituldave:
3+1/3=10/3
She wrote it as (3+1)/3
:)
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