Answer:
t = -1, 2
Step-by-step explanation:
Step 1: Define
h(t) = -5t² + 5t + 10
Step 2: Factor
h(t) = -5(t² - t - 2)
h(t) = -5(t - 2)(t + 1)
Step 3: Find roots
0 = -5(t - 2)(t + 1)
0 = (t - 2)(t + 1)
t - 2 = 0
t = 2
t + 1 = 0
t = -1
Answer:
140°
Step-by-step explanation:
<3 = 40 because they are vertical angles
<3 +<4 = 180 because they are same side interior angles
40 + <4 = 180
Subtract 40 from each side
40-40 + <4 = 180-40
<4 = 140
Answer:
![\sqrt3](https://tex.z-dn.net/?f=%5Csqrt3)
Step-by-step explanation:
To find:
The value of
= ?
Solution:
Kindly consider the equilateral
as attached in the answer area.
Let the side of triangle =
units
Let us draw the perpendicular from vertex A to side BC.
It will divide the side BC in two equal parts.
i.e. BD = DC = ![\frac{a}{2}](https://tex.z-dn.net/?f=%5Cfrac%7Ba%7D%7B2%7D)
Using Pythagorean Theorem in
:
![\text{Hypotenuse}^{2} = \text{Base}^{2} + \text{Perpendicular}^{2}](https://tex.z-dn.net/?f=%5Ctext%7BHypotenuse%7D%5E%7B2%7D%20%3D%20%5Ctext%7BBase%7D%5E%7B2%7D%20%2B%20%5Ctext%7BPerpendicular%7D%5E%7B2%7D)
Side AD = ![\frac{\sqrt3}{2}a](https://tex.z-dn.net/?f=%5Cfrac%7B%5Csqrt3%7D%7B2%7Da)
Using Trigonometric ratio:
![tan\theta = \dfrac{Perpendicular}{Base}](https://tex.z-dn.net/?f=tan%5Ctheta%20%3D%20%5Cdfrac%7BPerpendicular%7D%7BBase%7D)
![tanB = \dfrac{AD}{BD}](https://tex.z-dn.net/?f=tanB%20%3D%20%5Cdfrac%7BAD%7D%7BBD%7D)
Putting the values of AD and BD:
![tan60^\circ=\dfrac{\frac{\sqrt3}{2}a}{\frac{1}{2}a}\\\Rightarrow tan60^\circ = \bold{\sqrt3}](https://tex.z-dn.net/?f=tan60%5E%5Ccirc%3D%5Cdfrac%7B%5Cfrac%7B%5Csqrt3%7D%7B2%7Da%7D%7B%5Cfrac%7B1%7D%7B2%7Da%7D%5C%5C%5CRightarrow%20tan60%5E%5Ccirc%20%3D%20%5Cbold%7B%5Csqrt3%7D)
<h2>
Answer:</h2>
a)
The probability that both televisions work is: 0.42
b)
The probability at least one of the two televisions does not work is:
0.5833
<h2>
Step-by-step explanation:</h2>
There are a total of 9 televisions.
It is given that:
Three of the televisions are defective.
This means that the number of televisions which are non-defective are:
9-3=6
a)
The probability that both televisions work is calculated by:
![=\dfrac{6_C_2}{9_C_2}](https://tex.z-dn.net/?f=%3D%5Cdfrac%7B6_C_2%7D%7B9_C_2%7D)
( Since 6 televisions are in working conditions and out of these 6 2 are to be selected.
and the total outcome is the selection of 2 televisions from a total of 9 televisions)
Hence, we get:
![=\dfrac{\dfrac{6!}{2!\times (6-2)!}}{\dfrac{9!}{2!\times (9-2)!}}\\\\\\=\dfrac{\dfrac{6!}{2!\times 4!}}{\dfrac{9!}{2!\times 7!}}\\\\\\=\dfrac{5}{12}\\\\\\=0.42](https://tex.z-dn.net/?f=%3D%5Cdfrac%7B%5Cdfrac%7B6%21%7D%7B2%21%5Ctimes%20%286-2%29%21%7D%7D%7B%5Cdfrac%7B9%21%7D%7B2%21%5Ctimes%20%289-2%29%21%7D%7D%5C%5C%5C%5C%5C%5C%3D%5Cdfrac%7B%5Cdfrac%7B6%21%7D%7B2%21%5Ctimes%204%21%7D%7D%7B%5Cdfrac%7B9%21%7D%7B2%21%5Ctimes%207%21%7D%7D%5C%5C%5C%5C%5C%5C%3D%5Cdfrac%7B5%7D%7B12%7D%5C%5C%5C%5C%5C%5C%3D0.42)
b)
The probability at least one of the two televisions does not work:
Is equal to the probability that one does not work+probability both do not work.
Probability one does not work is calculated by:
![=\dfrac{3_C_1\times 6_C_1}{9_C_2}\\\\\\=\dfrac{\dfrac{3!}{1!\times (3-1)!}\times \dfrac{6!}{1!\times (6-1)!}}{\dfrac{9!}{2!\times (9-2)!}}\\\\\\=\dfrac{3\times 6}{36}\\\\\\=\dfrac{1}{2}\\\\\\=0.5](https://tex.z-dn.net/?f=%3D%5Cdfrac%7B3_C_1%5Ctimes%206_C_1%7D%7B9_C_2%7D%5C%5C%5C%5C%5C%5C%3D%5Cdfrac%7B%5Cdfrac%7B3%21%7D%7B1%21%5Ctimes%20%283-1%29%21%7D%5Ctimes%20%5Cdfrac%7B6%21%7D%7B1%21%5Ctimes%20%286-1%29%21%7D%7D%7B%5Cdfrac%7B9%21%7D%7B2%21%5Ctimes%20%289-2%29%21%7D%7D%5C%5C%5C%5C%5C%5C%3D%5Cdfrac%7B3%5Ctimes%206%7D%7B36%7D%5C%5C%5C%5C%5C%5C%3D%5Cdfrac%7B1%7D%7B2%7D%5C%5C%5C%5C%5C%5C%3D0.5)
and the probability both do not work is:
![=\dfrac{3_C_2}{9_C_2}\\\\\\=\dfrac{1}{12}\\\\\\=0.0833](https://tex.z-dn.net/?f=%3D%5Cdfrac%7B3_C_2%7D%7B9_C_2%7D%5C%5C%5C%5C%5C%5C%3D%5Cdfrac%7B1%7D%7B12%7D%5C%5C%5C%5C%5C%5C%3D0.0833)
Hence, Probability that atleast does not work is:
0.5+0.0833=0.5833