While loop to count iterations

Hello, I am new to matlab, and I am not sure how to use loops.

I am being asked to count the number of terms that keeps the equation k^2+2*k <100.

This is what I have, but all it is giving me is: count=1

count=0;
k=1:10;
while (k < 100)
    k=k.^2+2*k;
    count=count+1
end

Answer 1

[Image Analyst]

k = 1 : 10;
loopCounter = 1;
while loopCounter < length(k)
    theSum = k(loopCounter) .^ 2 + 2 * k(loopCounter)
    if theSum >= 100
        break; % Quit the loop
    end
    loopCounter=loopCounter+1
end
loopCounter % Show final value

Answer 2

[Walter Roberson]

k=1:10

is a vector.

while k<100

is a vector test equivalent to 10^2+2*10 = 120 and that is not less than 100 so the test is no longer true for all of the elements.

while all(k<100)

But after 1 step, the 10 component of k gets mapped to