A, B and D are already rational numbers, 0.4 itself is a rational number, two rational numbers make a product of rational number.
So A, B, D are the correct choices.
Are you sure it asks for rational numbers, not irrational number?
Answer:
can we go with D. 54 ?
the height and length is 9 and 6
9x6= 54
To evaluate the radius of the cone we proceed as follows:
V=1/3 πr²h
plugging in the values, v=88π, h=8 ft
step 1
88π1/3πr²(8)
step 2
88π=8/3πr²
step 3
divide both sides by π
88=8/3r²
multiply both sides by 3/(8)
88(3/8)=r²
step 4
simplify
33=r²
step 5
get the square root
r=√33
Thus the mistake that Fatima made was:
<span> In step 3, Fatima did not multiply 88 by the reciprocal of 8/3 </span>
4 cos² x - 3 = 0
4 cos² x = 3
cos² x = 3/4
cos x = ±(√3)/2
Fixing the squared cosine doesn't discriminate among quadrants. There's one in every quadrant
cos x = ± cos(π/6)
Let's do plus first. In general, cos x = cos a has solutions x = ±a + 2πk integer k
cos x = cos(π/6)
x = ±π/6 + 2πk
Minus next.
cos x = -cos(π/6)
cos x = cos(π - π/6)
cos x = cos(5π/6)
x = ±5π/6 + 2πk
We'll write all our solutions as
x = { -5π/6, -π/6, π/6, 5π/6 } + 2πk integer k
Answer:
Option 3 - 
Step-by-step explanation:
Given : Perpendicular to the line 
; containing the point (4,4).
To Find : An equation for the line with the given properties ?
Solution :
We know that,
When two lines are perpendicular then slope of one equation is negative reciprocal of another equation.
Slope of the equation
Converting into slope form 
,
Where m is the slope.
The slope of the equation is 
The slope of the perpendicular equation is 
The required slope is 
The required equation is 
Substitute point (x,y)=(4,4)
Substitute back in equation,
Therefore, The required equation for the line is
So, Option 3 is correct.
