Question

if sin a + cos a = 1 then the value of
sin a . cos a is:-

a) 0
b) 1
c) 2
d) -2

URGENT​

Answer 1

Answer:

-2

Step-by-step explanation:

Answer 2

Answer:

0

Step-by-step explanation:

$sin a + cos a = 1 \\( sin a + cos a)^2= 1 ^2\\sin^2 a+cos^2a+2sina *cosa=1\\1+2sina *cosa=1\\2sina *cosa=0\\sina *cosa=0$