The slope of first line is m 1= ( 1 - 0 ) / ( - 2 - ( - 6 ) );
m = 1 / 4 ;
Because the second line is perpendicular to the first line, m2 * m1 = - 1 ;
m2 * ( 1 / 4 ) = -1;
m2 = - 4 ;
The equation of the second line is : y - 3 = ( - 4 )( x - 2 );
y - 3 = -4x + 8 ;
y = -4x + 11.
Use cosine rule,
cos(A)=(b^2+c^2-a^2)/(2bc)
=(10^2+12^2-6^2)/(2*10*12)
=13/15
A=29.926 degrees.................................(A)
cos(B)=(c^2+a^2-b^2)/(2ca)
=(12^2+6^2-10^2)/(2*12*6)
=5/9
B=56.251 degrees.................................(B)
cos(C)=(a^2+b^2-c^2)/(2ab)
=(6^2+10^2-12^2)/(2*6*10)
=-1/15
C=93.823 degrees.................................(C)
Check:29.926+56.251+93.823=180.0 degrees....ok
It's dependent on the context. A book may ask you to find the f'(x) of a function and you may have to use a u sub in your problem which requires you to find the dy/dx of what you substitute. So in this case both would be used.
Greetings from Brasil...
According to the statement of the question, we can assemble the following system of equation
X = 7 + 3Y i
X + Y = 75 ii
So, multiplying ii by -1 and adding with i
X = 7 + 3Y
- X - Y = - 75
- Y = 7 + 3Y - 75
4Y = 68
Y = 17
for X we will use ii:
X + Y = 75
X + 17 = 75
X = 58
The smaller number is: 17
I don’t know what the options are but I think it is 95 because 120-25 = 95
