Do you have a picture to go with that? I can’t solve it without any info.
Answer:
1/sqrt10
Step-by-step explanation:
1) Find out cosA using formula (cosA)^2+(sinA)^2=1
The module of cosA= sqrt (1- (-3/5)^2)= sqrt 16/25=4/5
So cosA=-4/5 or cosA=4/5.
Due to the condition 270degrees< A<360 degrees, 0<cosA<1 that's why cosA=4/5.
2) Find sinA/2 using a formula cosA= 1-2sinA/2*sinA/2 where cosA=4/5.
(sinA/2)^2= 0.1
sinA= sqrt 0.1= 1/ sqrt10 or sinA= - sqrt 0.1= -1/sqrt10
But 270°< A< 360°, then 270/2°<A/2<360/2°
135°<A/2<180°, so sinA/2 must be positive and the only correct answer is
sin A/2= 1/sqrt10
Answer:
its 40
Step-by-step explanation:
180-100=80
80/2= 40
Answer:
14. A. Commutative Property of Addition.
15. D. k=54
Step-by-step explanation:
6 + 9 = 9 + 6 is an example of the Commutative Property of Addition so that is your answer.
k + (-12) = 42. What you do is add the 12 to both sides to get your answer.
k=54 is your answer.
