Recall that
sin(<em>a</em> + <em>b</em>) = sin(<em>a</em>) cos(<em>b</em>) + cos(<em>a</em>) sin(<em>b</em>)
sin(<em>a</em> - <em>b</em>) = sin(<em>a</em>) cos(<em>b</em>) - cos(<em>a</em>) sin(<em>b</em>)
Adding these together gives
sin(<em>a</em> + <em>b</em>) + sin(<em>a</em> - <em>b</em>) = 2 sin(<em>a</em>) cos(<em>b</em>)
To get 14 cos(39<em>x</em>) sin(19<em>x</em>) on the right side, multiply both sides by 7 and replace <em>a</em> = 19<em>x</em> and <em>b</em> = 39<em>x</em> :
7 (sin(19<em>x</em> + 39<em>x</em>) + sin(19<em>x</em> - 39<em>x</em>)) = 14 cos(39<em>x</em>) sin(19<em>x</em>)
7 (sin(58<em>x</em>) + sin(-20<em>x</em>)) = 14 cos(39<em>x</em>) sin(19<em>x</em>)
7 (sin(58<em>x</em>) - sin(20<em>x</em>)) = 14 cos(39<em>x</em>) sin(19<em>x</em>)
Subtract 10 from both sides.
Since the square of a number, x, equals a negative number, -1, the answer cannot be a real number because the square of a real number is always non-negative. Therefore, there is no real number solution to this equation.
Answer: <span>B. no real number solutions</span>
Answer:
Will
Step-by-step explanation:
The key word in this sentence is tomorrow, because tomorrow is in the future, therefore your answer is will.
Answer:
x 0.4
Step-by-step explanation:
Isolate the variable by dividing each side by factors that don't contain the variable.
Answer:
x=-8 and y=9
Step-by-step explanation:
rewrite the equations to x+2y=10,3x+4y=12
sub 2y from both sides x+2y-2y=10-2y
substitue x=10-2y in 3x +4y=12
3(-2y+10)+4y=12
distribute
add-30 to both sides
divide both sides by -2
y=9
sustitute 9 for y in -2y+10=x
x=-8
