Answer:
B
Step-by-step explanation:
they are similar and 7 / 5 = 21 / 15
The set is not closed
Example:
-4 * -3 = 12 this is not a negative integer
Answer:
Step-by-step explanation:
Let the number be y & reciprocal simply means inverse of the number
4×1/y=2×1/8 solving for y
4/y=2/8; y = 16
Answer:
x = 8√5
Step-by-step explanation:
In the figure attached, there are three right angle triangles.
So, by Pythagoras theorem,
y²+ 4² = z²
y² + 16 = z²------(1)
Similarly x² = 16² + y²--------(2)
and (16 + 4)² = x² + z²
20² = x² + z²-------(3)
Now we put the value of z² from equation 1 to equation 3
20² = x² + y² + 16
x² + y² = 400 - 16
x² + y² = 384
y² = 384 - x²------(4)
Now we put the value of y² from equation 4 to equation 2
x² = 16² + 384 - x²
2x² = 256 + 384
2x² = 640
x² = 320
x = 8√5
Therefore x = 8√5 will be the answer.
Answer:
Step-by-step explanation:

we take the LHS so here goes,

since ,
the identity becomes,

now, we know,
and 
the identity becomes,


sin A and cos A cancel out it becomes zero

Splitting the denominator the identity becomes

Hence,
