Question

DETERMINE as questões a seguir..​

Answer 1

a ) sen2 x + cos2 x = 1

( - 4√3 / 7 ) 2 + cos2 x = 1

48 / 49 + cos2 x = 1

cos2 x = 1 - 48 / 49

cos2 x = 49 / 49 - 48 / 49

cos2 x = 1 / 49

cosx = √1/49

cosx = 1 / 7

b) sen2 x + cos2 x = 1

sen2 x + ( 2 / 7 ) 2 = 1

sen2 x + 4 / 49 = 1

Sen2 x = 1 - 4 / 49

sen2 x = 49 / 49 - 4 / 49

sen2 x = 45 / 49

Sen x = √45 / 49

Sen x = 3√5 / 7

Answer 2

Resposta:

A)

R.: cos x = 1/7

B)

R.: sen x = 3√5/7

Explicação passo-a-passo:

A)

Sen x = -4√3/7

Cos x: (+)

X E 4°Q

Sen^2 x + cos^2 x = 1

(-4√3/7)^2 + cos^2 x = 1

16.3/49 + cos^2 x = 1

48/49 + cos^2 x = 1

Cos^2 x = 1 - 48/49

Cos^2 x = (49-48)/49

Cos^2 x = 1/49

Cos x = √(1/49)

Cos x = 1/7

4°Q é (+)

R.: cos x = 1/7

B)

Cos x = 2/7

Sen x = ? (+)

X E 1°Q

Sen^2 x + cos^2 x = 1

sen^2 x + (2/7)^2 = 1

Sen^2 x + 4/49 = 1

sen^2 x = 1 - 4/49

Sen^2 x = (49-4)/49

Sen^2 x = 45/49

Sen x = √45/√49

Sen x = √9.√5/7

Sen x = 3√5/7

1°Q é (+)

R.: sen x = 3√5/7