Answer:
4 d
Step-by-step explanation:
Given D is mid-point of BC and AD⊥AC
From right angle △DAC
cosC=
a/2
b
=
a
2b
...(i)
also from cosine formulae
cosC=
2ab
a
2
+b
2
−c
2
...(ii)
From (i) and (ii) we get
a
2b
=
2ab
a
2
+b
2
−c
2
⇒4b
2
=a
2
+b
2
−c
2
⇒b
2
=
3
a
2
−c
2
∴cosAcosC=
2bc
b
2
+c
2
−a
2
.
a
2b
=
ca
[(
3
a
2
−c
2
)+c
2
−a
2
]
=
3
2
(
ca
c
2
−a
2
)
Answer:
c, -2
Step-by-step explanation:
Answer:
2x
Step-by-step explanation:
7x= 7*x
5x=5*x
Subtract.
7-5=2
2*x=2x
So 2x is the answer.
Here we are given that C is between A and B.
So using the midpoint rule, sum of whole length AB will be addition of lengths AC and BC
so we can say that option C. CA is the correct choice as it satisfies the given condition.
0.4 has 4 tenths
Look at 0.4 as 0.40
Divide the 40 by 10 and get 4
-Hope this helped!
