Math, asked by Rahi39, 1 year ago

sinA + cosA = √2. Evaluate tanA + cotA

Answers

Answered by siddhartharao77
3
Given Sin A + cos A = root 2

On squaring both sides, we get

(sinA + cosA)^2 = (root)^2

We know that (a + b)^2 = a^2 + b^2 + 2ab

sin^2A + cos^2A + 2sinAcosA = 2

1 + 2sinAcosA = 2

2sinAcosA = 1

We know that 2sinAcosA = sin2A

sin2A = sin90

2A = 90

A = 45.


Now,

Tan A + cotA = Tan(45) + cot(45)

                      = 1 + 1

                      = 2.


Hope this helps!

Rahi39: After 2sinAcosA = 1, I didn't understand how to convert it
rohitkumargupta: nice
rohitkumargupta: bro
siddhartharao77: 2sinAcosA= sin2A

sin2A = 1

sin2A = sin90

2A = 90

A = 45
siddhartharao77: 2 SinA cosA = sin2A is the formula. Next step is sin90 = 1
Rahi39: oh....got it
Rahi39: Thank you
Answered by MANKOTIA
3
sinA+cosA =√2
squaring both sides we get
2sinAcosA =1. sinACosA=1/2
then tanA +cotA = sinA/cosA +cosA/sinA
=sin^2A +cos^2A)/sinA×cosA
=1/(1/2)
=2

siddhartharao77: I didn't understand the 3rd step. 2 sinAcosA = 1
siddhartharao77: On squaring both sides, The right side value will be 2 not 1.I think
MANKOTIA: (sinA+cosA)^2=(√2)^2 .sin^2A+cos^2A+2sinAcosA =2. then 1+2SinAcosA..=2. then2sinAcosA=2-1. then2sinAciosA=1
MANKOTIA: now this helps you.
siddhartharao77: Now I have understood. Kindly try to explain step by step.
MANKOTIA: next time,i will write all steps. [OM SAI RAM*,]
Rahi39: Thank you so much
siddhartharao77: Thank You
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