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2 years ago

I want to prove that (2tanx)/(sec^2x)=sin2x.

Mathematics

1 answer:

4vir4ik [10]2 years ago

5 0

Answer:

Step-by-step explanation:

$LHS = \frac{2 tan x}{Sec^{2} x}\\\\= 2tan x * \frac{1}{Sec^{2}x}\\\\= 2*\frac{Sinx }{Cos x}*Cos^{2}x\\\\= 2Sin x *Cos x\\= Sin 2x$

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The cost for 7 dance lessons is 82$. The cost for 11 lessons is 122$. Write and solve an equation to find the cost of 4 lessons

Juliette [100K]

Answer:

$52

Step-by-step explanation:

Using the equation

y=mx+c

82=7x+c

122=11x+c

11x-7x=122-82

4x=40

x=10

To get c

82=7(10)+c

82-70=c

c=12

For 4 lessons

y=10(4)+12=52

6 0

3 years ago

Whats 15 over 8 multiplied by 64 over 9?

Julli [10]

40/3. You mutiply top and bottom straight across, then simplify.

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3 years ago

Coal is carried from a mine in West Virginia to a power plant in New York in hopper cars on a long train. The automatic hopper c

Alenkasestr [34]

Step-by-step explanation:

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3 years ago

The sum of three numbers is 8. The third is 9

Ierofanga [76]

Answer:

→ First value is 1

→ Second value is 2

→ Third value is 5

Step-by-step explanation:

• let numbers be x, y and z

${ \tt{z = 8y - 9 - - - (eqn \: 1)}} \\ \\ { \tt{10x = 8y - 7 - - - (eqn \: 2)}} \\ \\ { \tt{x + y + z = 8 - - - (eqn \: 3)}}$

• from eqn 2, make x the subject:

${ \tt{x = \frac{8y - 7}{10} }} \\$

• substitute all variables in eqn 3:

${ \tt{ \frac{8y - 7}{10} + y + 8y - 9 = 8}} \\ \\ { \tt{8y - 7 + 10y + 80y - 90 = 80}} \\ \\ { \tt{98y = 177}} \\ \\ { \boxed{ \tt{ \: y = 1.8}}}$

• find z

${ \tt{z = 8y - 9}} \\ \\ { \tt{z = 8(1.8) - 9}} \\ \\ { \tt{z = 14.4 - 9}} \\ \\ { \boxed{ \tt{ \: z = 5.4 \: }}}$

• find x:

${ \tt{x = \frac{8(1.8) - 7}{10} }} \\ \\ { \tt{x = \frac{7.4}{10} }} \\ \\ { \boxed{ \tt{ \: x = 0.74 \: }}}$

Rounding to nearest value:

${ \boxed{ \rm{x = 1}}} \\ { \boxed{ \rm{y =2 }}} \\ { \boxed{ \rm{z = 5}}}$

7 0

2 years ago

This data represents the number of movies that were rented each day last week at A-Plus Video.

Keith_Richards [23]

For the mean you add them all up and divide by the ammount of numbers you added. So it would be 118

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2 years ago

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