Matematika

Pertanyaan

1.Cos 135' - Sin 330'
_______________=
tan 315' + Cos 225'
A.3/2 _/2
B.3_/2-4
C.1/2(3_/2-4)
D.1/2(_/2-4)
E.(_/2-4)
2.Sec a Tan^2 a + Sec a=
A.sec a
B.sec^2 a
C.sec^3 a
D.cosec a
E.cosec^2 a

mohon bantuan nya terhadam dua soal trigonometri diatas teman teman,terimakasih

1 Jawaban

  • 1) cos 135 = cos(180-45) = - cos 45 = - ½√2
    Sin 330 = sin (360-30) = - sin 30 = - ½
    Tan 315 = tan (360-45) = - tan 45 = - 1
    Cos 225 = cos (180+45) = - cos 45 = - ½√2
    Mk (-½√2 + ½)/(-1 - ½√2) × 2/2
    = (-√2 + 1)/(-2 - √2) × (-2 + √2)/(-2 + √2)
    = (2√2 - 2 - 2 + √2)/(4-2)
    = (3√2 - 4)/2 = ½ (3√2 - 4) (C)
    2) sec a ( tan²a + 1)
    = sec a ( sec²a)
    = sec³a (C)

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