no 44 caranya gimana bingung..?
Matematika
mikailrizky1
Pertanyaan
no 44 caranya gimana bingung..?
1 Jawaban
-
1. Jawaban whongaliem
44) I . 5.sin² A + 5cos² A = 5 (sin² A + cos² A)
= 5 (1)
= 5 ...... benar
II (sin A + cos A)² = sin² A + 2.sin A .cos A + cos² A
= (sin² A + cos² A) + 2.sin A. cos A
= 1 + 2.sin A .cos A ..... benar
III (sin A + cos A)² - 2 tan A . cos² A =
= sin² A + 2.sin A. cos A + cos² A - 2 .(sin A / cos A) cos ² A
= (sin² A + cos² A) + 2.sin A .cos A - 2.sin A .cos A
= sin² A + cos² A
= 1 ...... benar
[tex]IV . \frac{tan A - cot A}{tan A + cot A} = \frac{tan A - cot A}{tan A + cot A} X \frac{sin A .cos A}{sin A . cos A} [/tex]
[tex]= \frac{ sin^{2} A - cos^{2} A}{ sin^{2} A + cos^{2} A} [/tex]
[tex]= \frac{1 - cos^{2} A - cos^{2} A}{1} [/tex]
= 1 - 2.cos² A .... benar
jadi, semua pernyataan diatas benar .... jawaban : E