Question

If sinA= 3/5 and cosA=4/5,find the value of cos2A+sin2A
${?}^{2}$
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Answer 1

Answer:

cos2A+sin2A = 14/5

Step-by-step explanation:

sinA= 3/5

cosA=4/5

2 (4 / 5 ) + 2 ( 3 / 5 )

8/5 + 6/5

14/5

Answer 2

Step-by-step explanation:

cos2A= cos²A-sin²A

=(4/5)²-(3/5)²

=16/25-9/25 = (16-9)/25= 7/25

sin2A= 2sinAcosA

= 2(3/5)(4/5)

=24/25