Need help for questions in chapter one

[Hielly]

Hey i've been assigned with the whole chapter one for the holidays, and these are the questions i got stuck on ..

1) 
Find the gradient of each line below. Give answers to 2 decimal places.

2)     
For safety considerations, wheelchair ramps are constructed under regulated specifications. One regulation requires that the maximum gradient of a ramp exceeding 1200 mm in length is .
Does a ramp with gradient meet the specifications?

3)     
Find the gradient of a line perpendicular to another line which has a gradient of:
a)4

4)    
Find the gradient of a line which is perpendicular to the line with equation:
a) y = –5x + 2
 
5)     
Find the equation of the line passing through (3, –3) that makes an angle of 45° with the positive x-axis.

6)    
Find the equation of the line (in y = mx + c form) that:
(a) is perpendicular to the line with equation y = 3x + 1, passing through (–3, 6).
(b) is perpendicular to the line with equation –6x + 7y – 2 = 0, passing through (4, 0).


7)Find the equation of the line which passes through the point of intersection of the lines whose equations are 7x – 3y – 19 = 0 and 3x + 2y + 5 = 0, given that the required line is parallel to the line with equation –5x – 2y = 3.

     
Find the equation of a line containing the intersection of the lines with equations y = –3x + 4 and 5x – 3y + 40 = 0 which:
(a)has a gradient of 6/7

Thats for now, the other i have to review them and try and do it

Thanks! I've completed the whole chapter one except these questions

Edit: provide hints first so i can try and solve it myself

[Flaming_Arrow]

hint: when a line is a perpendicular to another line

[Hielly]

okay thanks, yep ill try those questions in italics with that formula. thanks

[Hielly]

hint: when a line is a perpendicular to another line

using this formula would be okay m1 = -1/m2 right ?

[kurrymuncher]

yeah thats fine

[Hielly]

Any hints for? 1,2,5,7,8

[Flaming_Arrow]

1. to find the gradient

7. make the equations equal each other(ie. solve for y or x then substitute.) and get the x and y points and we know of two lines are parallel

8. same as 7 but 

[Hielly]

1. to find the gradient

7. make the equations equal each other and get the x and y points and we know of two lines are parallel

8. same as 7 but 

for 1 i have already wrote tan(65) but its not correct

[Hielly]

oh wait hold on now im confused :S, how did you get -15 ?

[Flaming_Arrow]

oh wait hold on now im confused :S, how did you get -15 ?

because the line is going down meaning negative gradient

[Hielly]

hrm strange Tan(-15) = 0.856,
but the back of the book says -3.73

[mullums1]

hrm strange Tan(-15) = 0.856,
but the back of the book says -3.73

Maybe your calculator is in the wrong mode.

[Flaming_Arrow]

5. hint

[mullums1]

The formula states: Tan (theta) = M(gradient) The angle is the angle the line makes with the POSITIVE side of the x axis.

Using basic triangular angle calculation, you should get tan(105) = M (now this should be a negative value, as tan is negative in 2nd quadrant).

[Hielly]

hrm strange Tan(-15) = 0.856,
but the back of the book says -3.73

Maybe your calculator is in the wrong mode.

okay its in degrees but now it says
tan(-15)=-0.27