1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Alex Ar [27]
3 years ago
6

If sin (x+20°)=cos x. Find the value of x.

Mathematics
1 answer:
Maurinko [17]3 years ago
8 0
Sin(90-x)=cos(x), so 90-x=x+20. Solve for x:
90-x=x+20
70=2x
x=35 degrees.

Proof for the identity, sin(90-x)=cos(x):

Recall the following formulas:
sin(x)= \frac{opposite}{hypotenuse} \\
cos(x)= \frac{adjacent}{hypotenuse}

These sides are relative to the same reference angle, x. If you use the angle 90-x instead, then a few things change. The hypotenuse does not change, because the two triangles will share that side. Because the triangles are both right triangles, if they share the same hypotenuse, then they will form a rectangle. A rectangle has equal opposite sides. This is illustrated clearly in the attached image.

The side that was opposite of the angle x is the same length as the side that is adjacent to the angle 90-x, and the side that was adjacent to the angle x is the same length as the side that is opposite of the angle 90-x. So, if you have cos(x), it is the side adjacent to the angle x divided by the hypotenuse. The side adjacent of the angle x is equal to the side opposite of the angle 90-x. So cos(x) is also equal to the side opposite of the angle 90-x divided by the hypotenuse. Does this sound familiar? It is the trig function for sine. So sin(90-x)=cos(x).

You might be interested in
A line has the equation y=x. It is translated up by 3 units. What is the equation of the new line?
olga nikolaevna [1]
Since we are shifting equation up 3 units, the equation would be y=x+3
4 0
3 years ago
Read 2 more answers
Part of a tiling design is shown. The center is a regular hexagon. A square is on each side of the hexagon, and an equilateral t
VMariaS [17]

1,119.6 in. the answer is c my diddle.


Find the area of the hexagon which is 259.81

Find the area of the squares which is (6)100

Find the area of the triangles which was (6)43.3

259.81 + 600 + 259.8

519.6 + 600 = 1119.6

8 0
3 years ago
The expression 20l + 25g - 10 gives the number of dollars that Josie makes from mowing lawns and raking gardens.
vodka [1.7K]
20l + 25g -10
replace G with 4 and L with 3

20(3) + 25(4) - 10

60 + 100 - 10

160 - 10

150

he made $150
4 0
3 years ago
Which function is f(x) equal to f^-1(x)?
Morgarella [4.7K]

Answer:

c. f(x) x+1/x-1

Step-by-step explanation:

To answer this question, we need to check each answer one by one until we find the right one.  

y = (x+6)/(x-6)  

switch x and y  

x = (y+6)/(y-6)  

solve for y  

x(y-6) = y+6  

xy - 6x = y+6  

y(x-1) = 6x+6  

y = (6x+6) /(x-1) = 6(x+1)/(x-1)  

f^-1(x) = 6(x+1)/(x-1)  

y = (x+2)/(x-2)  

switch x and y  

x = (y+2)/(y-2)  

solve for y  

x(y-2) = y+2  

xy -2x = y+2  

y(x-1) = 2x+2  

y = (2x+2)/(x-1)  

f^-1(x) = 2(x+1)/(x-1)  

y = (x+1)/(x-1) ------ correct one  

switch x and y  

x = (y+1)/(y-1)  

solve for y  

x(y-1) = y+1  

xy - x = y+1  

y(x-1) = x+1  

y = (x+1)/(x-1)  

f^-1(x) = (x+1)/(x-1)  

f(x) = f^-1(x)

6 0
3 years ago
Read 2 more answers
In a circle, which ratio is equivalent to π?
garri49 [273]

A - Radius to Area

π r² is the formula to find the area in a circle

5 0
3 years ago
Read 2 more answers
Other questions:
  • If a cheetah runs 70 mph on a 100 meter track, and a lion runs 50 mph, how long would the track have to be so they finish at the
    15·2 answers
  • Fran swims at a speed of 2.6 mph in still water. The Lazy River flows at a speed of 0.4 mph. How long will it take Fran to swim
    14·1 answer
  • Do all rational functions have vertical asymptotes
    14·1 answer
  • How do you isolate the variable in x + 5 equals 12
    5·1 answer
  • Does every parallelogram have at least one right angle?
    5·1 answer
  • SOMEONE PLEASE HELP. SHOW WORK
    9·1 answer
  • The area of a trapezoid is 144 ft squared if the height is 8 feet and one of the bases is 12 ft what is the length of the other
    10·1 answer
  • A bag contains 2 green, 9 brown, 7 yellow, and 4 blue marbles.
    6·1 answer
  • Find the product.<br> 2/3 times -4/5<br> Plzzzzz help me ASAP
    5·1 answer
  • The ratio 15min to an hr can be writtin in the form 1:n
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!