Answer:
When you see a formula like this, try to operate, so you will see some identities sooner or later. In this case, we have a substraction identity:
\frac{cos ( \alpha - \beta )}{cos \alpha cos \beta } = \frac{cos \alpha cos \beta + sin \alpha sin \beta }{cos \alpha cos \beta } = 1 + tan α · tan β
Step-by-step explanation:
Answer:
x= -1.5, y= -1
Step-by-step explanation:
6x= -5+4y
x= (-5+4y) / 6
4((-5+4y) / 6) + 5y = -11
4(-5+4y) + 5*6y = -11*6
-20+16y+30y= -66
16y + 30y = -66+20 = -46
y(16 + 30) = -46
y= -46 / (16 + 30)
y= -46 / 46
y= -1
x= (-5+4(-1)) / 6
x= (-5-4) / 6
x= -9 /6
x= -1.5
Answer:
30
Step-by-step explanation:
A=pq
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2
Answer:
x = -7/40
, y = -11/20
Step-by-step explanation:
Solve the following system:
{12 x - 2 y = -1 | (equation 1)
4 x + 6 y = -4 | (equation 2)
Subtract 1/3 × (equation 1) from equation 2:
{12 x - 2 y = -1 | (equation 1)
0 x+(20 y)/3 = (-11)/3 | (equation 2)
Multiply equation 2 by 3:
{12 x - 2 y = -1 | (equation 1)
0 x+20 y = -11 | (equation 2)
Divide equation 2 by 20:
{12 x - 2 y = -1 | (equation 1)
0 x+y = (-11)/20 | (equation 2)
Add 2 × (equation 2) to equation 1:
{12 x+0 y = (-21)/10 | (equation 1)
0 x+y = -11/20 | (equation 2)
Divide equation 1 by 12:
{x+0 y = (-7)/40 | (equation 1)
0 x+y = -11/20 | (equation 2)
Collect results:
Answer: {x = -7/40
, y = -11/20
