tolong di jawab nya soal matdas

a + b = 45°
misalkan a-b = 0

cot β /(1+cot β)
= (cos β/sin β)/(1+(cos β/sin β))
= cos β/(sin β+cos β)

maka
(cot A/(1+cot A))+(cot B/(1+cot B))
= (cos A/(sin A+cos A))/(cos B/(sin B+cos B))
= (cos A.cos B)/(sin A.sin B+sin A.cos B+cos A.sin B+cos A.cos B)
*dengan menggunakan identitas trigonometri maka*
= (1/2(1/2√(2)+1))/((-1/2(1/2√(2)-1)) + (1/2(1/2√(2)+1)) + (1/2(1/2√(2))) + (1/2(1/2√(2)))
*eliminasi 1/2
= (1/2√(2)+1)/((-1/2√(2)+1) + (1/2√(2)+1) + (1/2√(2)) + (1/2√(2)))
*sederhanakan penyebut (operasi penjumlahan dan pengurangan)*
= (1/2√(2)+1)/ (√(2) +2)
= (1/2√(2)+1)/ (2(1/2√(2)+1)
*eliminasi (1/2√(2)+1) dari pembilang dan penyebut*
= 1/2

maaf kalau salah
permisalanya maksa banget^^