sendo tgx 4/5 0<x<pi/2 qual é o valor de secx senx e cosx?

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Por favor me ajudemmmmm, 10 pontos

zonic-the-hedgehog-2

tgx = 4/5 , x ∈ I

We have :

1/cos²x = tg²x + 1

<=> 1/cos²x = (4/5)² + 1 = 41/25

<=> cos²x = 25/41

<=> cosx = 5√41 / 41

=> tgx = senx/cosx

<=> tgx . cosx = senx

<=> 4/5 . 5√41 / 41 = 4√41 / 41

=> secx = 1/cosx =√41 / 5