trig
posted by y912f .
can you please show me in steps how to find f(1+a)
in this equation
f(x)=2x^2+4x+6
i know that you will plug in 1+a anywhere there is x. but after that i get confused.
also can you tell me how to find the domain and range of a relation
for ex. 2x+5y=10
thanks for your help!

trig 
Reiny
f(x)=2x^2+4x+6
f(1+a) = 2(1+a)^2 + 4(1+a) + 6
= 2(1 + 2a + a^2) + 4 + 4a + 6
= 2 4a 2a^2 + 10 + 4a
= 2a^2 + 8
for 2x+5y=10 both the domain and range are the real numbers
You are looking at a slanted line, (slope=2/5), so you will find the graph for whatever x you use, and for whatever y you use.
This is true for all straight line graphs, which are neither vertical nor horizontal. 
trig 
y912f
ok,thanks alot.. what about this one : y=2x^25

trig 
Reiny
this is a vertical parabola, meaning it opens either upwards or downwards
the domain of any vertical parabola is the set of real numbers
for the range:
if the parabola opens up, then y ≥ the y value of the vertex
if the parabola opens down, then y ≤ the y value of the vertex
in this case
Domain : x any real number
Range : y ≥ 5, y being real 
trig 
y912f
ok. so do u mean that to figure this out u always have to graph the relation?

trig 
Reiny
no, you just have to find the vertex.
Here is a quick way to find the vertex:
if y = ax^2 + bx + c
then the x of the vertex is b/(2a)
sub that back into the function to find the y value. 
trig 
y912f
im sry im still kinda confused. can you show me once again please and explain everything you do thnks:
y=2x+3
y=4/square root of x^2+81
thnks alot!! 
trig 
Reiny
btw, why are you calling this "trig" ?

trig 
y912f
its in the first chapter of my trig course. i know its review frm geometry and alg
Respond to this Question
Similar Questions

maths
I am really facing difficulty in maths. I do my best to improve in maths but after entering in the examination hall during my exams, i just get confused. please help The proper name for the subject is mathematics or just "math" for … 
MAth!PLease Help!
5. Find the x and y intercepts of each linear equation. Be sure to write your answers as ordered pairs. a.y=3x6 b.6y=x+2 Set x = 0 and y = 0 to find the intercepts. will that get me 2 thingys for each.? 
Math Analysis
Tell if the function is symmetric with respect to the xaxis, yaxis, and origin. 3. 8x^2  2y^2 = 12 ==> I got that it was symmetric to both the x and yaxes. Is this right? 
Math
Determine the zeros of the function 3x^2 8=10x. I know I rewrite it as 3x^2 10x8 = 0 But then what do I doI'm totally confusedAnswers are {2,4} {2,4} {2/3,4} {2/3,4} Please direct me or show the steps, just don't give me the … 
algebra
Find the inverse of the following function. Find the domain, range, and asymptotes of each function. Graph both functions on the same coordinate plane x/3 f(x)=4+e ( if this makes sense, not sure how else to show it. the x/3 is after … 
Trig
Let f and g be two invertible functions such that f^1(x)=5/x+4 and g(x)=4(x2). Find f(g(5)). Show your steps please so I can see how to do it. Thank you! :) 
math
Find the equation of the tangent line to the graph of f(x) = 2x − 6/x + 1 at the point at which x = 0. (Let x be the independent variable and y be the dependent variable.) I got this question wrong. I thought the answer would … 
PHYSICS 1
The vector signs are above each letter (I just don't know how to show it that way) A= 145 units @ 190 deg. B= 75 units @ 288 deg. C= 210 units @ 85 deg. D= 105 units @ 355 deg. How do I use the component Method with these given magnitude … 
Biochem
You prepare a 1L solution of 0.5 M imidazole. (pKa= 7.05). Calculate the pH of the solution after you add 0.1 moles of HCl. I need to create an ICE table. I also know I need to use the Henderson Hasselbalch equation but I'm confused … 
Math, Algebra
I asked these questions yesterday and thanked whomever helping me before clicking the links. When the links were just google searches, however, they didn't help me seeing as I already did that. The google search calculator doesn't …