bantu jawabbb

<p>Jawaban&nbsp;</p><p><i>opsi jawaban tidak ada yg sesuai</i></p><p>&nbsp;</p><p><strong>Pembahasan&nbsp;</strong></p><p>cos²A + sin² A = 1</p><p>&lt;=&gt; (⅔)² + sin²A = 1</p><p>&lt;=&gt; sin A = ⅓√5 &nbsp; (lancip)&nbsp;</p><p>&nbsp;</p><p>sin²B + (3/5)² = 1</p><p>&lt;=&gt; sin B = 4/5 &nbsp;(lancip)&nbsp;</p><p>&nbsp;</p><p>cos (A - B) = cos A. cos B + sin A. sin B</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= ⅔. 3/5 + ⅓√5. 4/5</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= 2/5 + (4√5)/15</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= (2(3 + 2√5))/15</p><p>Opsi jawaban tidak ada yg sesuai</p>