Hi there!
We are given:
cos(7x)cos(4x) = -1 - sin(7x)sin(4x)
Begin by moving all terms with variables to one side:
cos(7x)cos(4x) + sin(7x)sin(4x) = -1
The corresponding trig identity is cos(A - B). Thus:
cos(7x - 4x) = cos(7x)cos(4x) + sin(7x)sin(4x) = -1
cos(3x) = -1
cos = -1 at π, so:
3x = π
x = π/3
We can also find another solution. Let 3π = -1:
3x = 3π
x = π
Thus, solutions on [0, 2π) are π/3 and π.
Answer:
Obj B, by 1 g/cm^3
Step-by-step explanation:
Obj A = 12g / 8cm^3 = 3g / 2cm^3 = 1.5 g/cm^3
Obj B = 20g / 8cm^3 = 5g / 2cm^3 = 2.5 g/cm^3
2.5 - 1.5 = 1 g/cm^3
Answer:
5
Step-by-step explanation:
1.24 times 3 = 3.72
.95 (the value of pence to a pound in decimal form) = 2.85
6.18 for the teapot
2.72+2.85+6.18=11.75
She now has £8.25 left (20-11.75).
8.25/1.57=the amount of plates she can buy: 5.25477707006, so 5 with some money left
Distraibutiv peorpoty
a(b+c)=ab+ac
we have
3a+7+2(3+a)
distribute first
2(3+a)=6+2a
now we have
3a+7+6+2a
move like terms together
3a+2a+7+6
add lke terms
5a+13
Answer:
t° = 11° s°= 71°
Step-by-step explanation:
79° + t° =90° (Given)
t°= 90° - 79°
t°= 11°
s°+79°+11°+19° =180° (angles on an str line)
s° = 180° - 109°
s° = 71°
