Answer:
<em>cos a = -1.28 and 0.78</em>
Step-by-step explanation:
The question is not properly written. This is the correct question:
If sina×tan(a) = 1/2, find cosa
According to trigonometry identity;
tan a = sina/cosa
sina×tan(a) = sin a * sina/cosa
sin²a/cos a = 1/2
(1-cos²a)/cosa = 1/2
Cross multiply
2(1-cos²a) = cos a
2 - 2 cos²a = cos a
2cos²a + cos a - 2 = 0
Let P = cos a
2P² + P -2 = 0
P = -1 ±√1-4(2(2)/2(2)
P = -1 ±√1+16/4
P = -1 ±√17/4
P = -1±4.12/4
P = -1-4.12/4 and -1+4.12/4
P = -5.12/4 and 3.12/4
P = -1.28 and 0.78
Since P = cos a
<em>Hence cos a = -1.28 and 0.78</em>
Answer:
it would take about 11 to 13 days
Step-by-step explanation:
Answer:
6.78ft/sec
Step-by-step explanation:
From the question, dx/dt= 3.9 ft/sec
We are looking for Dy/dt
From geometry,vof this case the relationship between x and y is needed here, there is two similar triangle that exhibited by the man and the lamb
12/y= 5.1/(y-x)
Then ,cross multiply, we have
12(y-x)=5.1y
12y-12x=5.1y
12y-5.1y=12x
6.9y=12x
y=( 12/6.9)x
Differentiating implicitly the bother sides with respect to t, we have
Dy/dt= ( 12/6.9)dx/dt
But dx/dt= 3.9 ft/sec
Then Dy/dt= ( 12/6.9)× 3.9
Dy/dt=6.78ft/sec
Hence, the rate that the tip of the person's shadow moves away from the lamppost when the person is 9 ft away from the lampost is 6.78ft/sec
CHECK THE ATTACHMENT FOR THE FIQURE
5(6)+5(7)=65 using distributive property
Step-by-step explanation:
notice that 29 is one smaller than 30 and is being multiplied by 31. it is one smaller times 31 so 900 - 31 = 869. 31 is one bigger multiplied by 29 so 869 + 29 = 898. plus 1 = 899
25 times 25 = 625
625 - 26 = 599
599 + 24 = 623
plus 1 = 624
